diff --git a/src/cmd/pwd.c b/src/cmd/pwd.c
index 389f139..e161f81 100644
--- a/src/cmd/pwd.c
+++ b/src/cmd/pwd.c
@@ -10,10 +10,9 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <sys/param.h>
+#include <unistd.h>
 
-char *getwd();
-
-main()
+int main()
 {
     char pathname[MAXPATHLEN + 1];
 
diff --git a/src/cmd/rev.c b/src/cmd/rev.c
index 0d1fd26..803b186 100644
--- a/src/cmd/rev.c
+++ b/src/cmd/rev.c
@@ -8,23 +8,22 @@
 char line[N];
 FILE *input;
 
-main(argc,argv)
-char **argv;
+int main(int argc, char **argv)
 {
-    register i,c;
+    int i, c;
+
     input = stdin;
     do {
-        if(argc>1) {
-            if((input=fopen(argv[1],"r"))==NULL) {
-                fprintf(stderr,"rev: cannot open %s\n",
-                    argv[1]);
+        if (argc > 1) {
+            if ((input = fopen(argv[1], "r")) == NULL) {
+                fprintf(stderr, "rev: cannot open %s\n", argv[1]);
                 exit(1);
             }
         }
-        for(;;){
-            for(i=0;i<N;i++) {
+        for (;;) {
+            for (i = 0; i < N; i++) {
                 line[i] = c = getc(input);
-                switch(c) {
+                switch (c) {
                 case EOF:
                     goto eof;
                 default:
@@ -34,13 +33,13 @@ char **argv;
                 }
                 break;
             }
-            while(--i>=0)
-                putc(line[i],stdout);
-            putc('\n',stdout);
+            while (--i >= 0)
+                putc(line[i], stdout);
+            putc('\n', stdout);
         }
 eof:
         fclose(input);
         argc--;
         argv++;
-    } while(argc>1);
+    } while (argc > 1);
 }
diff --git a/src/cmd/rm.c b/src/cmd/rm.c
index c6d4b60..c3d7327 100644
--- a/src/cmd/rm.c
+++ b/src/cmd/rm.c
@@ -4,21 +4,25 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#include <unistd.h>
+#include <sys/dir.h>
 #include <sys/param.h>
 #include <sys/stat.h>
-#include <sys/dir.h>
-#include <sys/file.h>
 
-int fflg;       /* -f force - supress error messages */
-int iflg;       /* -i interrogate user on each file */
-int rflg;       /* -r recurse */
+int fflg; /* -f force - supress error messages */
+int iflg; /* -i interrogate user on each file */
+int rflg; /* -r recurse */
 
-int errcode;    /* true if errors occured */
+int errcode; /* true if errors occured */
 
-main(argc, argv)
-    char *argv[];
+static int rm(char arg[], int level);
+static int dotname(char *s);
+static int yes(void);
+static void append(char *name);
+
+int main(int argc, char *argv[])
 {
-    register char *arg;
+    char *arg;
 
     fflg = !isatty(0);
     iflg = 0;
@@ -34,7 +38,7 @@ main(argc, argv)
             break;
 
         while (*++arg != '\0')
-            switch(*arg) {
+            switch (*arg) {
             case 'f':
                 fflg++;
                 break;
@@ -60,26 +64,25 @@ main(argc, argv)
     }
 
     while (--argc > 0)
-        (void) rm(*++argv, 0);
+        (void)rm(*++argv, 0);
 
     exit(errcode != 0);
 }
 
-char    *path;      /* pointer to malloc'ed buffer for path */
-char    *pathp;     /* current pointer to end of path */
-int pathsz;     /* size of path */
+char *path;  /* pointer to malloc'ed buffer for path */
+char *pathp; /* current pointer to end of path */
+int pathsz;  /* size of path */
 
 /*
  * Return TRUE if sucessful. Recursive with -r (rflg)
  */
-rm(arg, level)
-    char arg[];
+int rm(char arg[], int level)
 {
-    int ok;             /* true if recursive rm succeeded */
-    struct stat buf;        /* for finding out what a file is */
-    struct direct *dp;      /* for reading a directory */
-    DIR *dirp;          /* for reading a directory */
-    char prevname[MAXNAMLEN + 1];   /* previous name for -r */
+    int ok;                       /* true if recursive rm succeeded */
+    struct stat buf;              /* for finding out what a file is */
+    struct direct *dp;            /* for reading a directory */
+    DIR *dirp;                    /* for reading a directory */
+    char prevname[MAXNAMLEN + 1]; /* previous name for -r */
     char *cp;
 
     if (dotname(arg)) {
@@ -91,9 +94,9 @@ rm(arg, level)
             fprintf(stderr, "rm: %s nonexistent\n", arg);
             errcode++;
         }
-        return (0);     /* error */
+        return (0); /* error */
     }
-    if ((buf.st_mode&S_IFMT) == S_IFDIR) {
+    if ((buf.st_mode & S_IFMT) == S_IFDIR) {
         if (!rflg) {
             if (!fflg) {
                 fprintf(stderr, "rm: %s directory\n", arg);
@@ -106,14 +109,14 @@ rm(arg, level)
             if (!yes())
                 return (0); /* didn't remove everything */
         }
-        if (access(arg, R_OK|W_OK|X_OK) != 0) {
+        if (access(arg, R_OK | W_OK | X_OK) != 0) {
             if (rmdir(arg) == 0)
                 return (1); /* salvaged: removed empty dir */
             if (!fflg) {
                 fprintf(stderr, "rm: %s not changed\n", arg);
                 errcode++;
             }
-            return (0);     /* error */
+            return (0); /* error */
         }
         if ((dirp = opendir(arg)) == NULL) {
             if (!fflg) {
@@ -133,7 +136,7 @@ rm(arg, level)
             append(dp->d_name);
             closedir(dirp);
             ok = rm(path, level + 1);
-            for (cp = pathp; *--cp != '/' && cp > path; )
+            for (cp = pathp; *--cp != '/' && cp > path;)
                 ;
             pathp = cp;
             *cp++ = '\0';
@@ -146,17 +149,15 @@ rm(arg, level)
             }
             /* pick up where we left off */
             if (prevname[0] != '\0') {
-                while ((dp = readdir(dirp)) != NULL &&
-                    strcmp(prevname, dp->d_name) != 0)
+                while ((dp = readdir(dirp)) != NULL && strcmp(prevname, dp->d_name) != 0)
                     ;
             }
             /* skip the one we just failed to delete */
             if (!ok) {
                 dp = readdir(dirp);
                 if (dp != NULL && strcmp(cp, dp->d_name)) {
-                    fprintf(stderr,
-            "rm: internal synchronization error: %s, %s, %s\n",
-                        arg, cp, dp->d_name);
+                    fprintf(stderr, "rm: internal synchronization error: %s, %s, %s\n", arg, cp,
+                            dp->d_name);
                 }
                 strcpy(prevname, dp->d_name);
             }
@@ -186,9 +187,8 @@ rm(arg, level)
         if (!yes())
             return (0);
     } else if (!fflg) {
-        if ((buf.st_mode&S_IFMT) != S_IFLNK && access(arg, W_OK) < 0) {
-            printf("rm: override protection %o for %s? ",
-                buf.st_mode&0777, arg);
+        if ((buf.st_mode & S_IFMT) != S_IFLNK && access(arg, W_OK) < 0) {
+            printf("rm: override protection %o for %s? ", buf.st_mode & 0777, arg);
             if (!yes())
                 return (0);
         }
@@ -206,24 +206,25 @@ rm(arg, level)
 /*
  * boolean: is it "." or ".." ?
  */
-dotname(s)
-    char *s;
+int dotname(char *s)
 {
-    if (s[0] == '.')
-        if (s[1] == '.')
+    if (s[0] == '.') {
+        if (s[1] == '.') {
             if (s[2] == '\0')
                 return (1);
             else
                 return (0);
-        else if (s[1] == '\0')
+        } else if (s[1] == '\0') {
             return (1);
+        }
+    }
     return (0);
 }
 
 /*
  * Get a yes/no answer from the user.
  */
-yes()
+int yes()
 {
     int i, b;
 
@@ -236,10 +237,9 @@ yes()
 /*
  * Append 'name' to 'path'.
  */
-append(name)
-    char *name;
+void append(char *name)
 {
-    register int n;
+    int n;
 
     n = strlen(name);
     if (path == NULL) {
diff --git a/src/cmd/rmail.c b/src/cmd/rmail.c
index c67214d..d3f8342 100644
--- a/src/cmd/rmail.c
+++ b/src/cmd/rmail.c
@@ -6,68 +6,61 @@
 **  It calls sendmail giving it a -f option built from these
 **  lines.
 */
+#include <paths.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 #include <strings.h>
 #include <sysexits.h>
-#include <paths.h>
 
-typedef char    bool;
-#define TRUE    1
-#define FALSE   0
+typedef char bool;
+#define TRUE 1
+#define FALSE 0
 
-bool    Debug;
+bool Debug;
 
-main(argc, argv)
-    char **argv;
+int main(int argc, char **argv)
 {
-    FILE *out;  /* output to sendmail */
-    char lbuf[1024];    /* one line of the message */
-    char from[512];     /* accumulated path of sender */
-    char ufrom[512];    /* user on remote system */
-    char sys[512];      /* a system in path */
-    char junk[1024];    /* scratchpad */
+    FILE *out;       /* output to sendmail */
+    char lbuf[1024]; /* one line of the message */
+    char from[512];  /* accumulated path of sender */
+    char ufrom[512]; /* user on remote system */
+    char sys[512];   /* a system in path */
+    char junk[1024]; /* scratchpad */
     char cmd[2000];
-    register char *cp;
-    register char *uf = ufrom;  /* ptr into ufrom */
+    char *cp;
+    char *uf = ufrom; /* ptr into ufrom */
     int i;
 
 #ifdef DEBUG
-    if (argc > 1 && strcmp(argv[1], "-T") == 0)
-    {
+    if (argc > 1 && strcmp(argv[1], "-T") == 0) {
         Debug = TRUE;
         argc--;
         argv++;
     }
 #endif
-    if (argc < 2)
-    {
+    if (argc < 2) {
         fprintf(stderr, "Usage: rmail user ...\n");
         exit(EX_USAGE);
     }
 
-    (void) strcpy(from, "");
-    (void) strcpy(ufrom, "/dev/null");
+    (void)strcpy(from, "");
+    (void)strcpy(ufrom, "/dev/null");
 
-    for (;;)
-    {
-        (void) fgets(lbuf, sizeof lbuf, stdin);
+    for (;;) {
+        (void)fgets(lbuf, sizeof lbuf, stdin);
         if (strncmp(lbuf, "From ", 5) != 0 && strncmp(lbuf, ">From ", 6) != 0)
             break;
-        (void) sscanf(lbuf, "%s %s", junk, ufrom);
+        (void)sscanf(lbuf, "%s %s", junk, ufrom);
         cp = lbuf;
-        for (;;)
-        {
-            cp = index(cp+1, 'r');
-            if (cp == NULL)
-            {
-                register char *p = rindex(uf, '!');
+        for (;;) {
+            cp = index(cp + 1, 'r');
+            if (cp == NULL) {
+                char *p = rindex(uf, '!');
 
-                if (p != NULL)
-                {
+                if (p != NULL) {
                     *p = '\0';
-                    (void) strcpy(sys, uf);
+                    (void)strcpy(sys, uf);
                     uf = p + 1;
                     break;
                 }
@@ -77,29 +70,28 @@ main(argc, argv)
             if (Debug)
                 printf("cp='%s'\n", cp);
 #endif
-            if (strncmp(cp, "remote from ", 12)==0)
+            if (strncmp(cp, "remote from ", 12) == 0)
                 break;
         }
         if (cp != NULL)
-            (void) sscanf(cp, "remote from %s", sys);
-        (void) strcat(from, sys);
-        (void) strcat(from, "!");
+            (void)sscanf(cp, "remote from %s", sys);
+        (void)strcat(from, sys);
+        (void)strcat(from, "!");
 #ifdef DEBUG
         if (Debug)
             printf("ufrom='%s', sys='%s', from now '%s'\n", uf, sys, from);
 #endif
     }
-    (void) strcat(from, uf);
+    (void)strcat(from, uf);
 
-    (void) sprintf(cmd, "%s -ee -f%s -i", _PATH_SENDMAIL, from);
-    while (*++argv != NULL)
-    {
-        (void) strcat(cmd, " '");
+    (void)sprintf(cmd, "%s -ee -f%s -i", _PATH_SENDMAIL, from);
+    while (*++argv != NULL) {
+        (void)strcat(cmd, " '");
         if (**argv == '(')
-            (void) strncat(cmd, *argv + 1, strlen(*argv) - 2);
+            (void)strncat(cmd, *argv + 1, strlen(*argv) - 2);
         else
-            (void) strcat(cmd, *argv);
-        (void) strcat(cmd, "'");
+            (void)strcat(cmd, *argv);
+        (void)strcat(cmd, "'");
     }
 #ifdef DEBUG
     if (Debug)
@@ -110,8 +102,7 @@ main(argc, argv)
     while (fgets(lbuf, sizeof lbuf, stdin))
         fputs(lbuf, out);
     i = pclose(out);
-    if ((i & 0377) != 0)
-    {
+    if ((i & 0377) != 0) {
         fprintf(stderr, "pclose: status 0%o\n", i);
         exit(EX_OSERR);
     }
diff --git a/src/cmd/rmdir.c b/src/cmd/rmdir.c
index 96db2be..038c184 100644
--- a/src/cmd/rmdir.c
+++ b/src/cmd/rmdir.c
@@ -9,10 +9,9 @@
  */
 #include <stdio.h>
 #include <stdlib.h>
+#include <unistd.h>
 
-main(argc,argv)
-    int argc;
-    char **argv;
+int main(int argc, char **argv)
 {
     int errors = 0;
 
@@ -20,11 +19,12 @@ main(argc,argv)
         fprintf(stderr, "usage: %s directory ...\n", argv[0]);
         exit(1);
     }
-    while (--argc)
+    while (--argc) {
         if (rmdir(*++argv) < 0) {
             fprintf(stderr, "rmdir: ");
-            perror(*argv);;
+            perror(*argv);
             errors++;
         }
+    }
     exit(errors != 0);
 }
diff --git a/src/cmd/size.c b/src/cmd/size.c
index 6aee5d1..f208961 100644
--- a/src/cmd/size.c
+++ b/src/cmd/size.c
@@ -2,19 +2,17 @@
  * size
  */
 #ifdef CROSS
-#   include </usr/include/stdio.h>
+#include </usr/include/stdio.h>
 #else
-#   include <stdio.h>
+#include <stdio.h>
 #endif
+#include <a.out.h>
 #include <stdlib.h>
 #include <unistd.h>
-#include <a.out.h>
 
 int header;
 
-int
-main(argc, argv)
-char **argv;
+int main(int argc, char **argv)
 {
     struct exec buf;
     long sum;
@@ -22,12 +20,12 @@ char **argv;
     FILE *f;
 
     while ((ch = getopt(argc, argv, "h")) != EOF) {
-        switch(ch) {
+        switch (ch) {
         case 'h':
         default:
             fprintf(stderr, "Usage:\n");
             fprintf(stderr, "  size file...\n");
-            return(1);
+            return (1);
         }
     }
     argc -= optind;
@@ -38,14 +36,13 @@ char **argv;
         argc++;
     }
 
-    for (nfiles=argc; argc--; argv++) {
-        if ((f = fopen(*argv, "r"))==NULL) {
+    for (nfiles = argc; argc--; argv++) {
+        if ((f = fopen(*argv, "r")) == NULL) {
             printf("size: %s not found\n", *argv);
             err++;
             continue;
         }
-        if (fread((char *)&buf, sizeof(buf), 1, f) != 1 ||
-            N_BADMAG(buf)) {
+        if (fread((char *)&buf, sizeof(buf), 1, f) != 1 || N_BADMAG(buf)) {
             printf("size: %s not an object file\n", *argv);
             fclose(f);
             err++;
@@ -55,8 +52,8 @@ char **argv;
             printf("text\tdata\tbss\tdec\thex\n");
             header = 1;
         }
-        printf("%u\t%u\t%u\t", buf.a_text,buf.a_data,buf.a_bss);
-        sum = (long) buf.a_text + (long) buf.a_data + (long) buf.a_bss;
+        printf("%u\t%u\t%u\t", buf.a_text, buf.a_data, buf.a_bss);
+        sum = (long)buf.a_text + (long)buf.a_data + (long)buf.a_bss;
         printf("%ld\t%lx", sum, sum);
         if (nfiles > 1)
             printf("\t%s", *argv);
diff --git a/src/cmd/sleep.c b/src/cmd/sleep.c
index d6d5497..9831e71 100644
--- a/src/cmd/sleep.c
+++ b/src/cmd/sleep.c
@@ -1,24 +1,24 @@
 #include <stdio.h>
 #include <stdlib.h>
+#include <unistd.h>
 
-main(argc, argv)
-char **argv;
+int main(int argc, char **argv)
 {
     int c, n;
     char *s;
 
     n = 0;
-    if(argc < 2) {
+    if (argc < 2) {
         printf("arg count\n");
         exit(0);
     }
     s = argv[1];
-    while(c = *s++) {
-        if(c<'0' || c>'9') {
+    while ((c = *s++)) {
+        if (c < '0' || c > '9') {
             printf("bad character\n");
             exit(0);
         }
-        n = n*10 + c - '0';
+        n = n * 10 + c - '0';
     }
     sleep(n);
 }
diff --git a/src/cmd/sort.c b/src/cmd/sort.c
index 9ec7b96..5646e7f 100644
--- a/src/cmd/sort.c
+++ b/src/cmd/sort.c
@@ -1,121 +1,88 @@
-#include <stdio.h>
-#include <string.h>
-#include <stdlib.h>
 #include <ctype.h>
-#include <signal.h>
-#include <unistd.h>
 #include <paths.h>
-#include <sys/types.h>
+#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
 #include <sys/stat.h>
+#include <sys/types.h>
+#include <unistd.h>
+#include <fcntl.h>
 
-#define L   1024
-#define N   7
-#define C   20
+#define L 1024
+#define N 7
+#define C 20
 #ifndef pdp11
-#define MEM (32*2048)
+#define MEM (32 * 2048)
 #else
-#define MEM (16*2048)
+#define MEM (16 * 2048)
 #endif
-#define NF  10
+#define NF 10
 
-#define rline(mp)   (fgets((mp)->l, L, (mp)->b) == NULL)
+#define rline(mp) (fgets((mp)->l, L, (mp)->b) == NULL)
 
-FILE    *is, *os;
-char    *dirtry[] = {_PATH_USRTMP, _PATH_TMP, NULL};
-char    **dirs;
-char    file1[30];
-char    *file = file1;
-char    *filep;
+FILE *is, *os;
+char *dirtry[] = { _PATH_USRTMP, _PATH_TMP, NULL };
+char **dirs;
+char file1[30];
+char *file = file1;
+char *filep;
 int nfiles;
-unsigned    nlines;
-unsigned    ntext;
+unsigned nlines;
+unsigned ntext;
 int *lspace;
-char    *tspace;
-int cmp(), cmpa();
-int (*compare)() = cmpa;
-char    *eol();
-void    term(int);
-int     mflg;
+char *tspace;
+void term(int);
+int mflg;
 int cflg;
 int uflg;
-char    *outfil;
-int unsafeout;  /*kludge to assure -m -o works*/
-char    tabchar;
-int     eargc;
-char    **eargv;
+char *outfil;
+int unsafeout; /*kludge to assure -m -o works*/
+char tabchar;
+int eargc;
+char **eargv;
 
 char zero[256];
 
-char    fold[256] = {
-    0200,0201,0202,0203,0204,0205,0206,0207,
-    0210,0211,0212,0213,0214,0215,0216,0217,
-    0220,0221,0222,0223,0224,0225,0226,0227,
-    0230,0231,0232,0233,0234,0235,0236,0237,
-    0240,0241,0242,0243,0244,0245,0246,0247,
-    0250,0251,0252,0253,0254,0255,0256,0257,
-    0260,0261,0262,0263,0264,0265,0266,0267,
-    0270,0271,0272,0273,0274,0275,0276,0277,
-    0300,0301,0302,0303,0304,0305,0306,0307,
-    0310,0311,0312,0313,0314,0315,0316,0317,
-    0320,0321,0322,0323,0324,0325,0326,0327,
-    0330,0331,0332,0333,0334,0335,0336,0337,
-    0340,0341,0342,0343,0344,0345,0346,0347,
-    0350,0351,0352,0353,0354,0355,0356,0357,
-    0360,0361,0362,0363,0364,0365,0366,0367,
-    0370,0371,0372,0373,0374,0375,0376,0377,
-    0000,0001,0002,0003,0004,0005,0006,0007,
-    0010,0011,0012,0013,0014,0015,0016,0017,
-    0020,0021,0022,0023,0024,0025,0026,0027,
-    0030,0031,0032,0033,0034,0035,0036,0037,
-    0040,0041,0042,0043,0044,0045,0046,0047,
-    0050,0051,0052,0053,0054,0055,0056,0057,
-    0060,0061,0062,0063,0064,0065,0066,0067,
-    0070,0071,0072,0073,0074,0075,0076,0077,
-    0100,0101,0102,0103,0104,0105,0106,0107,
-    0110,0111,0112,0113,0114,0115,0116,0117,
-    0120,0121,0122,0123,0124,0125,0126,0127,
-    0130,0131,0132,0133,0134,0135,0136,0137,
-    0140,0101,0102,0103,0104,0105,0106,0107,
-    0110,0111,0112,0113,0114,0115,0116,0117,
-    0120,0121,0122,0123,0124,0125,0126,0127,
-    0130,0131,0132,0173,0174,0175,0176,0177
+char fold[256] = {
+    0200, 0201, 0202, 0203, 0204, 0205, 0206, 0207, 0210, 0211, 0212, 0213, 0214, 0215, 0216, 0217,
+    0220, 0221, 0222, 0223, 0224, 0225, 0226, 0227, 0230, 0231, 0232, 0233, 0234, 0235, 0236, 0237,
+    0240, 0241, 0242, 0243, 0244, 0245, 0246, 0247, 0250, 0251, 0252, 0253, 0254, 0255, 0256, 0257,
+    0260, 0261, 0262, 0263, 0264, 0265, 0266, 0267, 0270, 0271, 0272, 0273, 0274, 0275, 0276, 0277,
+    0300, 0301, 0302, 0303, 0304, 0305, 0306, 0307, 0310, 0311, 0312, 0313, 0314, 0315, 0316, 0317,
+    0320, 0321, 0322, 0323, 0324, 0325, 0326, 0327, 0330, 0331, 0332, 0333, 0334, 0335, 0336, 0337,
+    0340, 0341, 0342, 0343, 0344, 0345, 0346, 0347, 0350, 0351, 0352, 0353, 0354, 0355, 0356, 0357,
+    0360, 0361, 0362, 0363, 0364, 0365, 0366, 0367, 0370, 0371, 0372, 0373, 0374, 0375, 0376, 0377,
+    0000, 0001, 0002, 0003, 0004, 0005, 0006, 0007, 0010, 0011, 0012, 0013, 0014, 0015, 0016, 0017,
+    0020, 0021, 0022, 0023, 0024, 0025, 0026, 0027, 0030, 0031, 0032, 0033, 0034, 0035, 0036, 0037,
+    0040, 0041, 0042, 0043, 0044, 0045, 0046, 0047, 0050, 0051, 0052, 0053, 0054, 0055, 0056, 0057,
+    0060, 0061, 0062, 0063, 0064, 0065, 0066, 0067, 0070, 0071, 0072, 0073, 0074, 0075, 0076, 0077,
+    0100, 0101, 0102, 0103, 0104, 0105, 0106, 0107, 0110, 0111, 0112, 0113, 0114, 0115, 0116, 0117,
+    0120, 0121, 0122, 0123, 0124, 0125, 0126, 0127, 0130, 0131, 0132, 0133, 0134, 0135, 0136, 0137,
+    0140, 0101, 0102, 0103, 0104, 0105, 0106, 0107, 0110, 0111, 0112, 0113, 0114, 0115, 0116, 0117,
+    0120, 0121, 0122, 0123, 0124, 0125, 0126, 0127, 0130, 0131, 0132, 0173, 0174, 0175, 0176, 0177
 };
 char nofold[256] = {
-    0200,0201,0202,0203,0204,0205,0206,0207,
-    0210,0211,0212,0213,0214,0215,0216,0217,
-    0220,0221,0222,0223,0224,0225,0226,0227,
-    0230,0231,0232,0233,0234,0235,0236,0237,
-    0240,0241,0242,0243,0244,0245,0246,0247,
-    0250,0251,0252,0253,0254,0255,0256,0257,
-    0260,0261,0262,0263,0264,0265,0266,0267,
-    0270,0271,0272,0273,0274,0275,0276,0277,
-    0300,0301,0302,0303,0304,0305,0306,0307,
-    0310,0311,0312,0313,0314,0315,0316,0317,
-    0320,0321,0322,0323,0324,0325,0326,0327,
-    0330,0331,0332,0333,0334,0335,0336,0337,
-    0340,0341,0342,0343,0344,0345,0346,0347,
-    0350,0351,0352,0353,0354,0355,0356,0357,
-    0360,0361,0362,0363,0364,0365,0366,0367,
-    0370,0371,0372,0373,0374,0375,0376,0377,
-    0000,0001,0002,0003,0004,0005,0006,0007,
-    0010,0011,0012,0013,0014,0015,0016,0017,
-    0020,0021,0022,0023,0024,0025,0026,0027,
-    0030,0031,0032,0033,0034,0035,0036,0037,
-    0040,0041,0042,0043,0044,0045,0046,0047,
-    0050,0051,0052,0053,0054,0055,0056,0057,
-    0060,0061,0062,0063,0064,0065,0066,0067,
-    0070,0071,0072,0073,0074,0075,0076,0077,
-    0100,0101,0102,0103,0104,0105,0106,0107,
-    0110,0111,0112,0113,0114,0115,0116,0117,
-    0120,0121,0122,0123,0124,0125,0126,0127,
-    0130,0131,0132,0133,0134,0135,0136,0137,
-    0140,0141,0142,0143,0144,0145,0146,0147,
-    0150,0151,0152,0153,0154,0155,0156,0157,
-    0160,0161,0162,0163,0164,0165,0166,0167,
-    0170,0171,0172,0173,0174,0175,0176,0177
+    0200, 0201, 0202, 0203, 0204, 0205, 0206, 0207, 0210, 0211, 0212, 0213, 0214, 0215, 0216, 0217,
+    0220, 0221, 0222, 0223, 0224, 0225, 0226, 0227, 0230, 0231, 0232, 0233, 0234, 0235, 0236, 0237,
+    0240, 0241, 0242, 0243, 0244, 0245, 0246, 0247, 0250, 0251, 0252, 0253, 0254, 0255, 0256, 0257,
+    0260, 0261, 0262, 0263, 0264, 0265, 0266, 0267, 0270, 0271, 0272, 0273, 0274, 0275, 0276, 0277,
+    0300, 0301, 0302, 0303, 0304, 0305, 0306, 0307, 0310, 0311, 0312, 0313, 0314, 0315, 0316, 0317,
+    0320, 0321, 0322, 0323, 0324, 0325, 0326, 0327, 0330, 0331, 0332, 0333, 0334, 0335, 0336, 0337,
+    0340, 0341, 0342, 0343, 0344, 0345, 0346, 0347, 0350, 0351, 0352, 0353, 0354, 0355, 0356, 0357,
+    0360, 0361, 0362, 0363, 0364, 0365, 0366, 0367, 0370, 0371, 0372, 0373, 0374, 0375, 0376, 0377,
+    0000, 0001, 0002, 0003, 0004, 0005, 0006, 0007, 0010, 0011, 0012, 0013, 0014, 0015, 0016, 0017,
+    0020, 0021, 0022, 0023, 0024, 0025, 0026, 0027, 0030, 0031, 0032, 0033, 0034, 0035, 0036, 0037,
+    0040, 0041, 0042, 0043, 0044, 0045, 0046, 0047, 0050, 0051, 0052, 0053, 0054, 0055, 0056, 0057,
+    0060, 0061, 0062, 0063, 0064, 0065, 0066, 0067, 0070, 0071, 0072, 0073, 0074, 0075, 0076, 0077,
+    0100, 0101, 0102, 0103, 0104, 0105, 0106, 0107, 0110, 0111, 0112, 0113, 0114, 0115, 0116, 0117,
+    0120, 0121, 0122, 0123, 0124, 0125, 0126, 0127, 0130, 0131, 0132, 0133, 0134, 0135, 0136, 0137,
+    0140, 0141, 0142, 0143, 0144, 0145, 0146, 0147, 0150, 0151, 0152, 0153, 0154, 0155, 0156, 0157,
+    0160, 0161, 0162, 0163, 0164, 0165, 0166, 0167, 0170, 0171, 0172, 0173, 0174, 0175, 0176, 0177
 };
 
-char    nonprint[256] = {
+char nonprint[256] = {
+    // clang-format off
     1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
     1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
     1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
@@ -132,9 +99,10 @@ char    nonprint[256] = {
     0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
     0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
     0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1
+    // clang-format on
 };
 
-char    dict[256] = {
+char dict[256] = {
     1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
     1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
     1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
@@ -153,7 +121,7 @@ char    dict[256] = {
     0,0,0,0,0,0,0,0,0,0,0,1,1,1,1,1
 };
 
-struct  field {
+struct field {
     char *code;
     char *ignore;
     int nflg;
@@ -161,26 +129,35 @@ struct  field {
     int bflg[2];
     int m[2];
     int n[2];
-}   fields[NF];
-struct field proto = {
-    nofold+128,
-    zero+128,
-    0,
-    1,
-    0,0,
-    0,-1,
-    0,0
-};
+} fields[NF];
+
+struct field proto = { nofold + 128, zero + 128, 0, 1, 0, 0, 0, -1, 0, 0 };
 int nfields;
-int     error = 1;
-char    *setfil();
+int error = 1;
 
-#define blank(c)    ((c) == ' ' || (c) == '\t')
+#define blank(c) ((c) == ' ' || (c) == '\t')
 
-main(argc, argv)
-char **argv;
+static int cmpa(char *pa, char *pb);
+static void copyproto(void);
+static void field(char *s, int k);
+static void diag(char *s, char *t);
+static void safeoutfil(void);
+static void sort(void);
+static void newfile(void);
+static void merge(int a, int b);
+static void oldfile(void);
+static char *setfil(int i);
+static void cant(char *f);
+static void qusort(char **a, char **l);
+static void disorder(char *s, char *t);
+static char *eol(char *p);
+static int number(char **ppa);
+
+int (*compare)(char *pa, char *pb) = cmpa;
+
+int main(int argc, char **argv)
 {
-    register a;
+    int a;
     extern char end[1];
     char *ep;
     char *arg;
@@ -190,84 +167,92 @@ char **argv;
     copyproto();
     eargv = argv;
     while (--argc > 0) {
-        if(**++argv == '-') for(arg = *argv;;) {
-            switch(*++arg) {
-            case '\0':
-                if(arg[-1] == '-')
-                    eargv[eargc++] = "-";
-                break;
+        if (**++argv == '-')
+            for (arg = *argv;;) {
+                switch (*++arg) {
+                case '\0':
+                    if (arg[-1] == '-')
+                        eargv[eargc++] = "-";
+                    break;
 
-            case 'o':
-                if(--argc > 0)
-                    outfil = *++argv;
-                continue;
+                case 'o':
+                    if (--argc > 0)
+                        outfil = *++argv;
+                    continue;
 
-            case 'T':
-                if (--argc > 0)
-                    dirtry[0] = *++argv;
-                continue;
+                case 'T':
+                    if (--argc > 0)
+                        dirtry[0] = *++argv;
+                    continue;
 
-            default:
-                field(++*argv,nfields>0);
+                default:
+                    field(++*argv, nfields > 0);
+                    break;
+                }
                 break;
             }
-            break;
-        } else if (**argv == '+') {
-            if(++nfields>=NF) {
-                diag("too many keys","");
+        else if (**argv == '+') {
+            if (++nfields >= NF) {
+                diag("too many keys", "");
                 exit(1);
             }
             copyproto();
-            field(++*argv,0);
+            field(++*argv, 0);
         } else
             eargv[eargc++] = *argv;
     }
     q = &fields[0];
-    for(a=1; a<=nfields; a++) {
+    for (a = 1; a <= nfields; a++) {
         p = &fields[a];
-        if(p->code != proto.code) continue;
-        if(p->ignore != proto.ignore) continue;
-        if(p->nflg != proto.nflg) continue;
-        if(p->rflg != proto.rflg) continue;
-        if(p->bflg[0] != proto.bflg[0]) continue;
-        if(p->bflg[1] != proto.bflg[1]) continue;
+        if (p->code != proto.code)
+            continue;
+        if (p->ignore != proto.ignore)
+            continue;
+        if (p->nflg != proto.nflg)
+            continue;
+        if (p->rflg != proto.rflg)
+            continue;
+        if (p->bflg[0] != proto.bflg[0])
+            continue;
+        if (p->bflg[1] != proto.bflg[1])
+            continue;
         p->code = q->code;
         p->ignore = q->ignore;
         p->nflg = q->nflg;
         p->rflg = q->rflg;
         p->bflg[0] = p->bflg[1] = q->bflg[0];
     }
-    if(eargc == 0)
+    if (eargc == 0)
         eargv[eargc++] = "-";
-    if(cflg && eargc>1) {
-        diag("can check only 1 file","");
+    if (cflg && eargc > 1) {
+        diag("can check only 1 file", "");
         exit(1);
     }
     safeoutfil();
 
     ep = end + MEM;
     lspace = (int *)sbrk(0);
-    while((int)brk(ep) == -1)
+    while ((int)brk(ep) == -1)
         ep -= 512;
 #ifndef vax
     brk(ep -= 512); /* for recursion */
 #endif
-    a = ep - (char*)lspace;
-    nlines = (a-L);
-    nlines /= (5*(sizeof(char *)/sizeof(char)));
-    ntext = nlines * 4 * (sizeof(char *)/sizeof(char));
+    a = ep - (char *)lspace;
+    nlines = (a - L);
+    nlines /= (5 * (sizeof(char *) / sizeof(char)));
+    ntext = nlines * 4 * (sizeof(char *) / sizeof(char));
     tspace = (char *)(lspace + nlines);
     a = -1;
-    for(dirs=dirtry; *dirs; dirs++) {
-        sprintf(filep=file1, "%s/stm%05uaa", *dirs, getpid());
+    for (dirs = dirtry; *dirs; dirs++) {
+        sprintf(filep = file1, "%s/stm%05uaa", *dirs, getpid());
         while (*filep)
             filep++;
         filep -= 2;
-        if ( (a=creat(file, 0600)) >=0)
+        if ((a = creat(file, 0600)) >= 0)
             break;
     }
-    if(a < 0) {
-        diag("can't locate temp","");
+    if (a < 0) {
+        diag("can't locate temp", "");
         exit(1);
     }
     close(a);
@@ -280,18 +265,18 @@ char **argv;
     if (signal(SIGTERM, SIG_IGN) != SIG_IGN)
         signal(SIGTERM, term);
     nfiles = eargc;
-    if(!mflg && !cflg) {
+    if (!mflg && !cflg) {
         sort();
         fclose(stdin);
     }
-    for(a = mflg|cflg?0:eargc; a+N<nfiles || unsafeout&&a<eargc; a=i) {
-        i = a+N;
-        if(i>=nfiles)
+    for (a = mflg | cflg ? 0 : eargc; a + N < nfiles || unsafeout && a < eargc; a = i) {
+        i = a + N;
+        if (i >= nfiles)
             i = nfiles;
         newfile();
         merge(a, i);
     }
-    if(a != nfiles) {
+    if (a != nfiles) {
         oldfile();
         merge(a, nfiles);
     }
@@ -299,19 +284,19 @@ char **argv;
     term(0);
 }
 
-sort()
+void sort()
 {
-    register char *cp;
-    register char **lp;
-    register lines, text, len;
+    char *cp;
+    char **lp;
+    int lines, text, len;
     int done = 0;
     int i = 0;
     char *f;
     char c;
 
-    if((f = setfil(i++)) == NULL)
+    if ((f = setfil(i++)) == NULL)
         is = stdin;
-    else if((is = fopen(f, "r")) == NULL)
+    else if ((is = fopen(f, "r")) == NULL)
         cant(f);
 
     do {
@@ -319,49 +304,49 @@ sort()
         lp = (char **)lspace;
         lines = nlines;
         text = ntext;
-        while(lines > 0 && text > 0) {
-            if(fgets(cp, L, is) == NULL) {
-                if(i >= eargc) {
+        while (lines > 0 && text > 0) {
+            if (fgets(cp, L, is) == NULL) {
+                if (i >= eargc) {
                     ++done;
                     break;
                 }
                 fclose(is);
-                if((f = setfil(i++)) == NULL)
+                if ((f = setfil(i++)) == NULL)
                     is = stdin;
-                else if((is = fopen(f, "r")) == NULL)
+                else if ((is = fopen(f, "r")) == NULL)
                     cant(f);
                 continue;
             }
             *lp++ = cp;
             len = strlen(cp) + 1; /* null terminate */
-            if(cp[len - 2] != '\n')
+            if (cp[len - 2] != '\n') {
                 if (len == L) {
                     diag("line too long (skipped): ", cp);
-                    while((c=getc(is)) != EOF && c != '\n')
+                    while ((c = getc(is)) != EOF && c != '\n')
                         /* throw it away */;
                     --lp;
                     continue;
                 } else {
-                    diag("missing newline before EOF in ",
-                        f ? f : "standard input");
+                    diag("missing newline before EOF in ", f ? f : "standard input");
                     /* be friendly, append a newline */
                     ++len;
                     cp[len - 2] = '\n';
                     cp[len - 1] = '\0';
                 }
+            }
             cp += len;
             --lines;
             text -= len;
         }
         qusort((char **)lspace, lp);
-        if(done == 0 || nfiles != eargc)
+        if (done == 0 || nfiles != eargc)
             newfile();
         else
             oldfile();
         clearerr(os);
-        while(lp > (char **)lspace) {
+        while (lp > (char **)lspace) {
             cp = *--lp;
-            if(*cp)
+            if (*cp)
                 fputs(cp, os);
             if (ferror(os)) {
                 error = 1;
@@ -369,231 +354,224 @@ sort()
             }
         }
         fclose(os);
-    } while(done == 0);
+    } while (done == 0);
 }
 
-struct merg
-{
-    char    l[L];
-    FILE    *b;
+struct merg {
+    char l[L];
+    FILE *b;
 } *ibuf[256];
 
-merge(a,b)
+void merge(int a, int b)
 {
-    struct  merg    *p;
-    register char   *cp, *dp;
-    register    i;
+    struct merg *p;
+    char *cp, *dp;
+    int i;
     struct merg **ip, *jp;
-    char    *f;
+    char *f;
     int j;
     int k, l;
     int muflg;
 
     p = (struct merg *)lspace;
     j = 0;
-    for(i=a; i < b; i++) {
+    for (i = a; i < b; i++) {
         f = setfil(i);
-        if(f == 0)
+        if (f == 0)
             p->b = stdin;
-        else if((p->b = fopen(f, "r")) == NULL)
+        else if ((p->b = fopen(f, "r")) == NULL)
             cant(f);
         ibuf[j] = p;
-        if(!rline(p))   j++;
+        if (!rline(p))
+            j++;
         p++;
     }
 
     do {
         i = j;
-        qusort((char **)ibuf, (char **)(ibuf+i));
+        qusort((char **)ibuf, (char **)(ibuf + i));
         l = 0;
-        while(i--) {
+        while (i--) {
             cp = ibuf[i]->l;
-            if(*cp == '\0') {
+            if (*cp == '\0') {
                 l = 1;
-                if(rline(ibuf[i])) {
+                if (rline(ibuf[i])) {
                     k = i;
-                    while(++k < j)
-                        ibuf[k-1] = ibuf[k];
+                    while (++k < j)
+                        ibuf[k - 1] = ibuf[k];
                     j--;
                 }
             }
         }
-    } while(l);
+    } while (l);
 
     clearerr(os);
     muflg = mflg & uflg | cflg;
     i = j;
-    while(i > 0) {
-        cp = ibuf[i-1]->l;
-        if (!cflg && (uflg == 0 || muflg || i == 1 ||
-            (*compare)(ibuf[i-1]->l,ibuf[i-2]->l))) {
+    while (i > 0) {
+        cp = ibuf[i - 1]->l;
+        if (!cflg && (uflg == 0 || muflg || i == 1 || (*compare)(ibuf[i - 1]->l, ibuf[i - 2]->l))) {
             fputs(cp, os);
             if (ferror(os)) {
                 error = 1;
                 term(0);
             }
         }
-        if(muflg){
-            cp = ibuf[i-1]->l;
+        if (muflg) {
+            cp = ibuf[i - 1]->l;
             dp = p->l;
             do {
-            } while((*dp++ = *cp++) != '\n');
+            } while ((*dp++ = *cp++) != '\n');
         }
-        for(;;) {
-            if(rline(ibuf[i-1])) {
+        for (;;) {
+            if (rline(ibuf[i - 1])) {
                 i--;
-                if(i == 0)
+                if (i == 0)
                     break;
-                if(i == 1)
+                if (i == 1)
                     muflg = uflg;
             }
             ip = &ibuf[i];
-            while(--ip>ibuf&&(*compare)(ip[0]->l,ip[-1]->l)<0){
+            while (--ip > ibuf && (*compare)(ip[0]->l, ip[-1]->l) < 0) {
                 jp = *ip;
-                *ip = *(ip-1);
-                *(ip-1) = jp;
+                *ip = *(ip - 1);
+                *(ip - 1) = jp;
             }
-            if(!muflg)
+            if (!muflg)
                 break;
-            j = (*compare)(ibuf[i-1]->l,p->l);
-            if(cflg) {
-                if(j > 0)
-                    disorder("disorder:",ibuf[i-1]->l);
-                else if(uflg && j==0)
-                    disorder("nonunique:",ibuf[i-1]->l);
-            } else if(j == 0)
+            j = (*compare)(ibuf[i - 1]->l, p->l);
+            if (cflg) {
+                if (j > 0)
+                    disorder("disorder:", ibuf[i - 1]->l);
+                else if (uflg && j == 0)
+                    disorder("nonunique:", ibuf[i - 1]->l);
+            } else if (j == 0)
                 continue;
             break;
         }
     }
     p = (struct merg *)lspace;
-    for(i=a; i<b; i++) {
+    for (i = a; i < b; i++) {
         fclose(p->b);
         p++;
-        if(i >= eargc)
+        if (i >= eargc)
             unlink(setfil(i));
     }
     fclose(os);
 }
 
-disorder(s,t)
-char *s, *t;
+void disorder(char *s, char *t)
 {
-    register char *u;
-    for(u=t; *u!='\n';u++) ;
+    char *u;
+
+    for (u = t; *u != '\n'; u++)
+        ;
     *u = 0;
-    diag(s,t);
+    diag(s, t);
     term(0);
 }
 
-newfile()
+void newfile()
 {
-    register char *f;
+    char *f;
 
     f = setfil(nfiles);
-    if((os=fopen(f, "w")) == NULL) {
-        diag("can't create ",f);
+    if ((os = fopen(f, "w")) == NULL) {
+        diag("can't create ", f);
         term(0);
     }
     nfiles++;
 }
 
-char *
-setfil(i)
+char *setfil(int i)
 {
-
-    if(i < eargc)
-        if(eargv[i][0] == '-' && eargv[i][1] == '\0')
-            return(0);
+    if (i < eargc) {
+        if (eargv[i][0] == '-' && eargv[i][1] == '\0')
+            return (0);
         else
-            return(eargv[i]);
+            return (eargv[i]);
+    }
     i -= eargc;
-    filep[0] = i/26 + 'a';
-    filep[1] = i%26 + 'a';
-    return(file);
+    filep[0] = i / 26 + 'a';
+    filep[1] = i % 26 + 'a';
+    return (file);
 }
 
-oldfile()
+void oldfile()
 {
-
-    if(outfil) {
-        if((os=fopen(outfil, "w")) == NULL) {
-            diag("can't create ",outfil);
+    if (outfil) {
+        if ((os = fopen(outfil, "w")) == NULL) {
+            diag("can't create ", outfil);
             term(0);
         }
     } else
         os = stdout;
 }
 
-safeoutfil()
+void safeoutfil()
 {
-    register int i;
-    struct stat obuf,ibuf;
+    int i;
+    struct stat obuf, ibuf;
 
-    if(!mflg||outfil==0)
+    if (!mflg || outfil == 0)
         return;
-    if(stat(outfil,&obuf)==-1)
+    if (stat(outfil, &obuf) == -1)
         return;
-    for(i=eargc-N;i<eargc;i++) {    /*-N is suff., not nec.*/
-        if(stat(eargv[i],&ibuf)==-1)
+    for (i = eargc - N; i < eargc; i++) { /*-N is suff., not nec.*/
+        if (stat(eargv[i], &ibuf) == -1)
             continue;
-        if(obuf.st_dev==ibuf.st_dev&&
-           obuf.st_ino==ibuf.st_ino)
+        if (obuf.st_dev == ibuf.st_dev && obuf.st_ino == ibuf.st_ino)
             unsafeout++;
     }
 }
 
-cant(f)
-char *f;
+void cant(char *f)
 {
     perror(f);
     term(0);
 }
 
-diag(s,t)
-char *s, *t;
+void diag(char *s, char *t)
 {
-    fputs("sort: ",stderr);
-    fputs(s,stderr);
-    fputs(t,stderr);
-    fputs("\n",stderr);
+    fputs("sort: ", stderr);
+    fputs(s, stderr);
+    fputs(t, stderr);
+    fputs("\n", stderr);
 }
 
-void term(sig)
-int sig;
+void term(int sig)
 {
-    register i;
+    int i;
 
     signal(SIGINT, SIG_IGN);
     signal(SIGHUP, SIG_IGN);
     signal(SIGTERM, SIG_IGN);
-    if(nfiles == eargc)
+    if (nfiles == eargc)
         nfiles++;
-    for(i=eargc; i<=nfiles; i++) {  /*<= in case of interrupt*/
-        unlink(setfil(i));  /*with nfiles not updated*/
+    for (i = eargc; i <= nfiles; i++) { /*<= in case of interrupt*/
+        unlink(setfil(i));              /*with nfiles not updated*/
     }
     _exit(error);
 }
 
-cmp(i, j)
-char *i, *j;
+int cmp(char *i, char *j)
 {
-    register char *pa, *pb;
+    char *pa, *pb;
     char *skip();
     char *code, *ignore;
     int a, b;
     int k;
     char *la, *lb;
-    register int sa;
+    int sa;
     int sb;
     char *ipa, *ipb, *jpa, *jpb;
     struct field *fp;
 
-    for(k = nfields>0; k<=nfields; k++) {
+    for (k = nfields > 0; k <= nfields; k++) {
         fp = &fields[k];
         pa = i;
         pb = j;
-        if(k) {
+        if (k) {
             la = skip(pa, fp, 1);
             pa = skip(pa, fp, 0);
             lb = skip(pb, fp, 1);
@@ -602,166 +580,166 @@ char *i, *j;
             la = eol(pa);
             lb = eol(pb);
         }
-        if(fp->nflg) {
-            if(tabchar) {
-                if(pa<la&&*pa==tabchar)
+        if (fp->nflg) {
+            if (tabchar) {
+                if (pa < la && *pa == tabchar)
                     pa++;
-                if(pb<lb&&*pb==tabchar)
+                if (pb < lb && *pb == tabchar)
                     pb++;
             }
-            while(blank(*pa))
+            while (blank(*pa))
                 pa++;
-            while(blank(*pb))
+            while (blank(*pb))
                 pb++;
             sa = sb = fp->rflg;
-            if(*pa == '-') {
+            if (*pa == '-') {
                 pa++;
                 sa = -sa;
             }
-            if(*pb == '-') {
+            if (*pb == '-') {
                 pb++;
                 sb = -sb;
             }
-            for(ipa = pa; ipa<la&&isdigit(*ipa); ipa++) ;
-            for(ipb = pb; ipb<lb&&isdigit(*ipb); ipb++) ;
+            for (ipa = pa; ipa < la && isdigit(*ipa); ipa++)
+                ;
+            for (ipb = pb; ipb < lb && isdigit(*ipb); ipb++)
+                ;
             jpa = ipa;
             jpb = ipb;
             a = 0;
-            if(sa==sb)
-                while(ipa > pa && ipb > pb)
-                    if(b = *--ipb - *--ipa)
+            if (sa == sb)
+                while (ipa > pa && ipb > pb)
+                    if ((b = *--ipb - *--ipa))
                         a = b;
-            while(ipa > pa)
-                if(*--ipa != '0')
-                    return(-sa);
-            while(ipb > pb)
-                if(*--ipb != '0')
-                    return(sb);
-            if(a) return(a*sa);
-            if(*(pa=jpa) == '.')
+            while (ipa > pa)
+                if (*--ipa != '0')
+                    return (-sa);
+            while (ipb > pb)
+                if (*--ipb != '0')
+                    return (sb);
+            if (a)
+                return (a * sa);
+            if (*(pa = jpa) == '.')
                 pa++;
-            if(*(pb=jpb) == '.')
+            if (*(pb = jpb) == '.')
                 pb++;
-            if(sa==sb)
-                while(pa<la && isdigit(*pa)
-                   && pb<lb && isdigit(*pb))
-                    if(a = *pb++ - *pa++)
-                        return(a*sa);
-            while(pa<la && isdigit(*pa))
-                if(*pa++ != '0')
-                    return(-sa);
-            while(pb<lb && isdigit(*pb))
-                if(*pb++ != '0')
-                    return(sb);
+            if (sa == sb)
+                while (pa < la && isdigit(*pa) && pb < lb && isdigit(*pb))
+                    if ((a = *pb++ - *pa++))
+                        return (a * sa);
+            while (pa < la && isdigit(*pa))
+                if (*pa++ != '0')
+                    return (-sa);
+            while (pb < lb && isdigit(*pb))
+                if (*pb++ != '0')
+                    return (sb);
             continue;
         }
         code = fp->code;
         ignore = fp->ignore;
-loop:
-        while(ignore[*pa])
+    loop:
+        while (ignore[*pa])
             pa++;
-        while(ignore[*pb])
+        while (ignore[*pb])
             pb++;
-        if(pa>=la || *pa=='\n')
-            if(pb<lb && *pb!='\n')
-                return(fp->rflg);
-            else continue;
-        if(pb>=lb || *pb=='\n')
-            return(-fp->rflg);
-        if((sa = code[*pb++]-code[*pa++]) == 0)
+        if (pa >= la || *pa == '\n') {
+            if (pb < lb && *pb != '\n')
+                return (fp->rflg);
+            else
+                continue;
+        }
+        if (pb >= lb || *pb == '\n')
+            return (-fp->rflg);
+        if ((sa = code[*pb++] - code[*pa++]) == 0)
             goto loop;
-        return(sa*fp->rflg);
+        return (sa * fp->rflg);
     }
-    if(uflg)
-        return(0);
-    return(cmpa(i, j));
+    if (uflg)
+        return (0);
+    return (cmpa(i, j));
 }
 
-cmpa(pa, pb)
-register char *pa, *pb;
+int cmpa(char *pa, char *pb)
 {
-    while(*pa == *pb) {
-        if(*pa++ == '\n')
-            return(0);
+    while (*pa == *pb) {
+        if (*pa++ == '\n')
+            return (0);
         pb++;
     }
-    return(
-        *pa == '\n' ? fields[0].rflg:
-        *pb == '\n' ?-fields[0].rflg:
-        *pb > *pa   ? fields[0].rflg:
-        -fields[0].rflg
-    );
+    return (*pa == '\n'   ? fields[0].rflg
+            : *pb == '\n' ? -fields[0].rflg
+            : *pb > *pa   ? fields[0].rflg
+                          : -fields[0].rflg);
 }
 
-char *
-skip(pp, fp, j)
-struct field *fp;
-char *pp;
+char *skip(char *pp, struct field *fp, int j)
 {
-    register i;
-    register char *p;
+    int i;
+    char *p;
 
     p = pp;
-    if( (i=fp->m[j]) < 0)
-        return(eol(p));
-    while(i-- > 0) {
-        if(tabchar != 0) {
-            while(*p != tabchar)
-                if(*p != '\n')
+    if ((i = fp->m[j]) < 0)
+        return (eol(p));
+    while (i-- > 0) {
+        if (tabchar != 0) {
+            while (*p != tabchar)
+                if (*p != '\n')
                     p++;
-                else goto ret;
-            if(i>0||j==0)
+                else
+                    goto ret;
+            if (i > 0 || j == 0)
                 p++;
         } else {
-            while(blank(*p))
+            while (blank(*p))
                 p++;
-            while(!blank(*p))
-                if(*p != '\n')
+            while (!blank(*p))
+                if (*p != '\n')
                     p++;
-                else goto ret;
+                else
+                    goto ret;
         }
     }
-    if(tabchar==0||fp->bflg[j])
-        while(blank(*p))
+    if (tabchar == 0 || fp->bflg[j])
+        while (blank(*p))
             p++;
     i = fp->n[j];
-    while(i-- > 0) {
-        if(*p != '\n')
+    while (i-- > 0) {
+        if (*p != '\n')
             p++;
-        else goto ret;
+        else
+            goto ret;
     }
 ret:
-    return(p);
+    return (p);
 }
 
-char *
-eol(p)
-register char *p;
+char *eol(char *p)
 {
-    while(*p != '\n') p++;
-    return(p);
+    while (*p != '\n')
+        p++;
+    return (p);
 }
 
-copyproto()
+void copyproto()
 {
-    register i;
-    register int *p, *q;
+    int i;
+    int *p, *q;
 
     p = (int *)&proto;
     q = (int *)&fields[nfields];
-    for(i=0; i<sizeof(proto)/sizeof(*p); i++)
+    for (i = 0; i < sizeof(proto) / sizeof(*p); i++)
         *q++ = *p++;
 }
 
-field(s,k)
-char *s;
+void field(char *s, int k)
 {
-    register struct field *p;
-    register d;
+    struct field *p;
+    int d;
+
     p = &fields[nfields];
     d = 0;
-    for(; *s!=0; s++) {
-        switch(*s) {
+    for (; *s != 0; s++) {
+        switch (*s) {
         case '\0':
             return;
 
@@ -770,14 +748,14 @@ char *s;
             break;
 
         case 'd':
-            p->ignore = dict+128;
+            p->ignore = dict + 128;
             break;
 
         case 'f':
-            p->code = fold+128;
+            p->code = fold + 128;
             break;
         case 'i':
-            p->ignore = nonprint+128;
+            p->ignore = nonprint + 128;
             break;
 
         case 'c':
@@ -793,7 +771,8 @@ char *s;
             break;
         case 't':
             tabchar = *++s;
-            if(tabchar == 0) s--;
+            if (tabchar == 0)
+                s--;
             continue;
 
         case 'r':
@@ -804,38 +783,44 @@ char *s;
             break;
 
         case '.':
-            if(p->m[k] == -1)   /* -m.n with m missing */
+            if (p->m[k] == -1) /* -m.n with m missing */
                 p->m[k] = 0;
-            d = &fields[0].n[0]-&fields[0].m[0];
+            d = &fields[0].n[0] - &fields[0].m[0];
 
         default:
-            p->m[k+d] = number(&s);
+            p->m[k + d] = number(&s);
         }
         compare = cmp;
     }
 }
 
-number(ppa)
-char **ppa;
+int number(char **ppa)
 {
     int n;
-    register char *pa;
+    char *pa;
+
     pa = *ppa;
     n = 0;
-    while(isdigit(*pa)) {
-        n = n*10 + *pa - '0';
+    while (isdigit(*pa)) {
+        n = n * 10 + *pa - '0';
         *ppa = pa++;
     }
-    return(n);
+    return (n);
 }
 
-#define qsexc(p,q) t= *p;*p= *q;*q=t
-#define qstexc(p,q,r) t= *p;*p= *r;*r= *q;*q=t
+#define qsexc(p, q) \
+    t = *p;         \
+    *p = *q;        \
+    *q = t
+#define qstexc(p, q, r) \
+    t = *p;             \
+    *p = *r;            \
+    *r = *q;            \
+    *q = t
 
-qusort(a,l)
-char **a, **l;
+void qusort(char **a, char **l)
 {
-    register char **i, **j;
+    char **i, **j;
     char **k;
     char **lp, **hp;
     int c;
@@ -843,38 +828,36 @@ char **a, **l;
     unsigned n;
 
 start:
-    if((n=l-a) <= 1)
+    if ((n = l - a) <= 1)
         return;
 
-
     n /= 2;
-    hp = lp = a+n;
+    hp = lp = a + n;
     i = a;
-    j = l-1;
+    j = l - 1;
 
-
-    for(;;) {
-        if(i < lp) {
-            if((c = (*compare)(*i, *lp)) == 0) {
+    for (;;) {
+        if (i < lp) {
+            if ((c = (*compare)(*i, *lp)) == 0) {
                 --lp;
                 qsexc(i, lp);
                 continue;
             }
-            if(c < 0) {
+            if (c < 0) {
                 ++i;
                 continue;
             }
         }
 
-loop:
-        if(j > hp) {
-            if((c = (*compare)(*hp, *j)) == 0) {
+    loop:
+        if (j > hp) {
+            if ((c = (*compare)(*hp, *j)) == 0) {
                 ++hp;
                 qsexc(hp, j);
                 goto loop;
             }
-            if(c > 0) {
-                if(i == lp) {
+            if (c > 0) {
+                if (i == lp) {
                     ++hp;
                     qstexc(i, hp, j);
                     i = ++lp;
@@ -889,21 +872,20 @@ loop:
             goto loop;
         }
 
-
-        if(i == lp) {
-            if(uflg)
-                for(k=lp+1; k<=hp;) **k++ = '\0';
-            if(lp-a >= l-hp) {
-                qusort(hp+1, l);
+        if (i == lp) {
+            if (uflg)
+                for (k = lp + 1; k <= hp;)
+                    **k++ = '\0';
+            if (lp - a >= l - hp) {
+                qusort(hp + 1, l);
                 l = lp;
             } else {
                 qusort(a, lp);
-                a = hp+1;
+                a = hp + 1;
             }
             goto start;
         }
 
-
         --lp;
         qstexc(j, lp, i);
         j = --hp;
diff --git a/src/cmd/split.c b/src/cmd/split.c
index b7fbe7f..ee8ff2b 100644
--- a/src/cmd/split.c
+++ b/src/cmd/split.c
@@ -3,22 +3,20 @@
 
 unsigned count = 1000;
 int fnumber;
-char    fname[100];
-char    *ifil;
-char    *ofil;
-FILE    *is;
-FILE    *os;
+char fname[100];
+char *ifil;
+char *ofil;
+FILE *is;
+FILE *os;
 
-main(argc, argv)
-char *argv[];
+int main(int argc, char *argv[])
 {
-    register i, c, f;
+    int i, c, f;
     int iflg = 0;
 
-    for(i=1; i<argc; i++)
-        if(argv[i][0] == '-')
-            switch(argv[i][1]) {
-
+    for (i = 1; i < argc; i++)
+        if (argv[i][0] == '-')
+            switch (argv[i][1]) {
             case '\0':
                 iflg = 1;
                 continue;
@@ -33,50 +31,49 @@ char *argv[];
             case '7':
             case '8':
             case '9':
-                count = atoi(argv[i]+1);
+                count = atoi(argv[i] + 1);
                 continue;
             }
-        else if(iflg)
+        else if (iflg)
             ofil = argv[i];
         else {
             ifil = argv[i];
             iflg = 2;
         }
-    if(iflg != 2)
+    if (iflg != 2)
         is = stdin;
-    else
-        if((is=fopen(ifil,"r")) == NULL) {
-            perror(ifil);
-            exit(1);
-        }
-    if(ofil == 0)
+    else if ((is = fopen(ifil, "r")) == NULL) {
+        perror(ifil);
+        exit(1);
+    }
+    if (ofil == 0)
         ofil = "x";
 
 loop:
     f = 1;
-    for(i=0; i<count; i++)
-    do {
-        c = getc(is);
-        if(c == EOF) {
-            if(f == 0)
-                fclose(os);
-            exit(0);
-        }
-        if(f) {
-            for(f=0; ofil[f]; f++)
-                fname[f] = ofil[f];
-            fname[f++] = fnumber/26 + 'a';
-            fname[f++] = fnumber%26 + 'a';
-            fname[f] = '\0';
-            fnumber++;
-            if((os=fopen(fname,"w")) == NULL) {
-                fprintf(stderr,"Cannot create output\n");
-                exit(1);
+    for (i = 0; i < count; i++)
+        do {
+            c = getc(is);
+            if (c == EOF) {
+                if (f == 0)
+                    fclose(os);
+                exit(0);
             }
-            f = 0;
-        }
-        putc(c, os);
-    } while(c != '\n');
+            if (f) {
+                for (f = 0; ofil[f]; f++)
+                    fname[f] = ofil[f];
+                fname[f++] = fnumber / 26 + 'a';
+                fname[f++] = fnumber % 26 + 'a';
+                fname[f] = '\0';
+                fnumber++;
+                if ((os = fopen(fname, "w")) == NULL) {
+                    fprintf(stderr, "Cannot create output\n");
+                    exit(1);
+                }
+                f = 0;
+            }
+            putc(c, os);
+        } while (c != '\n');
     fclose(os);
     goto loop;
 }
diff --git a/src/cmd/sum.c b/src/cmd/sum.c
index 0b30496..0a1f398 100644
--- a/src/cmd/sum.c
+++ b/src/cmd/sum.c
@@ -4,18 +4,17 @@
 #include <stdio.h>
 #include <stdlib.h>
 
-main(argc,argv)
-char **argv;
+int main(int argc, char **argv)
 {
-    register unsigned sum;
-    register i, c;
-    register FILE *f;
-    register long nbytes;
+    unsigned sum;
+    int i, c;
+    FILE *f;
+    long nbytes;
     int errflg = 0;
 
     i = 1;
     do {
-        if(i < argc) {
+        if (i < argc) {
             if ((f = fopen(argv[i], "r")) == NULL) {
                 fprintf(stderr, "sum: Can't open %s\n", argv[i]);
                 errflg += 10;
@@ -27,8 +26,8 @@ char **argv;
         nbytes = 0;
         while ((c = getc(f)) != EOF) {
             nbytes++;
-            if (sum&01)
-                sum = (sum>>1) + 0x8000;
+            if (sum & 01)
+                sum = (sum >> 1) + 0x8000;
             else
                 sum >>= 1;
             sum += c;
@@ -36,13 +35,13 @@ char **argv;
         }
         if (ferror(f)) {
             errflg++;
-            fprintf(stderr, "sum: read error on %s\n", argc>1?argv[i]:"-");
+            fprintf(stderr, "sum: read error on %s\n", argc > 1 ? argv[i] : "-");
         }
-        printf("%05u%6ld", sum, (nbytes+BUFSIZ-1)/BUFSIZ);
-        if(argc > 2)
+        printf("%05u%6ld", sum, (nbytes + BUFSIZ - 1) / BUFSIZ);
+        if (argc > 2)
             printf(" %s", argv[i]);
         printf("\n");
         fclose(f);
-    } while(++i < argc);
+    } while (++i < argc);
     exit(errflg);
 }
diff --git a/src/cmd/sync.c b/src/cmd/sync.c
index 6803c99..203cfd4 100644
--- a/src/cmd/sync.c
+++ b/src/cmd/sync.c
@@ -1,3 +1,5 @@
+#include <unistd.h>
+
 int main()
 {
     sync();