Added a tiny implementation of readline library, based on linenoise sources.

See https://github.com/antirez/linenoise for details.

Implemented a routine atexit() in libc.

Pdc modified to use readline library.

include/.gitignore

@@ -0,0 +1 @@
+readline

lib/Makefile

@@ -1,5 +1,5 @@
 TOPSRC          = $(shell cd ..; pwd)
-SUBDIR		= startup libc libcurses libtermlib libwiznet
+SUBDIR		= startup libc libcurses libtermlib libwiznet libreadline
 PROG		= ar as aout ld nm ranlib size strip
 
 CFLAGS          += -std=gnu89 -fno-builtin -g -Werror -Wall -DCROSS -I. \

lib/libreadline/Makefile

@@ -0,0 +1,17 @@
+TOPSRC		= $(shell cd ../..; pwd)
+include $(TOPSRC)/target.mk
+
+vpath %.c $(TOPSRC)/src/libreadline
+
+CFLAGS		+= -B$(TOPSRC)/lib/ $(DEFS) -Wa,-x -Wall -Werror
+
+OBJS		= readline.o
+
+all:            ../libreadline.a
+
+../libreadline.a: ../ar ../ranlib $(OBJS)
+		../ar rc $@ $(OBJS)
+		../ranlib $@
+
+clean:
+		rm -f *~ *.o a.out *.a

rootfs.manifest

@@ -754,6 +754,7 @@ filemode 0664
 dir /include
 dir /include/arpa
 dir /include/machine
+dir /include/readline
 dir /include/smallc
 dir /include/smallc/sys
 dir /include/sys
@@ -794,6 +795,8 @@ file /include/paths.h
 file /include/psout.h
 file /include/pwd.h
 file /include/ranlib.h
+file /include/readline/history.h
+file /include/readline/readline.h
 file /include/regexp.h
 file /include/setjmp.h
 file /include/sgtty.h
@@ -906,6 +909,7 @@ target sys/syslog.h
 file /lib/crt0.o
 file /lib/libc.a
 file /lib/libcurses.a
+file /lib/libreadline.a
 file /lib/libtermlib.a
 file /lib/libwiznet.a
 file /lib/retroImage

src/cmd/pdc/.gitignore

@@ -0,0 +1,3 @@
+pdc
+y.tab.c
+y.tab.h

src/cmd/pdc/Makefile

@@ -8,7 +8,8 @@ OBJS            = pdc.o
 LDFLAGS         += -g
 
 CFLAGS		+= -Werror -Wall -Os
-CFLAGS          += -DGCC_COMPAT -DHAVE_CPP_VARARG_MACRO_GCC
+CFLAGS          += -DGCC_COMPAT -DHAVE_CPP_VARARG_MACRO_GCC -DHAVE_READLINE
+LIBS            = -lreadline -lc
 
 all:            pdc
 

src/libc/stdio/exit.c

@@ -1,14 +1,48 @@
 #include <stdlib.h>
 #include <unistd.h>
 
+struct atexit {                 /* entry allocated per atexit() call */
+    struct atexit *next;        /* next enty in a list */
+    void (*func)(void);         /* callback function */
+};
+
 int errno;
+struct atexit *__atexit;        /* points to head of LIFO stack */
 
 extern void _cleanup();
 
 void
 exit (code)
-	int code;
+    int code;
 {
-	_cleanup();
+    register struct atexit *p;
-	_exit (code);
+
+    for (p = __atexit; p; p = p->next)
+        (*p->func)();
+    _cleanup();
+    _exit (code);
+}
+
+/*
+ * Register a function to be performed at exit.
+ */
+int
+atexit(fn)
+    void (*fn)();
+{
+    static struct atexit __atexit0; /* one guaranteed table */
+    register struct atexit *p;
+
+    p = __atexit;
+    if (! p) {
+        p = &__atexit0;
+    } else {
+        p = malloc(sizeof(struct atexit));
+        if (! p)
+            return -1;
+        p->next = __atexit;
+    }
+    p->func = fn;
+    __atexit = p;
+    return 0;
 }

src/libreadline/LICENSE

@@ -0,0 +1,25 @@
+Copyright (c) 2010-2014, Salvatore Sanfilippo <antirez at gmail dot com>
+Copyright (c) 2010-2013, Pieter Noordhuis <pcnoordhuis at gmail dot com>
+
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are met:
+
+* Redistributions of source code must retain the above copyright notice,
+  this list of conditions and the following disclaimer.
+
+* Redistributions in binary form must reproduce the above copyright notice,
+  this list of conditions and the following disclaimer in the documentation
+  and/or other materials provided with the distribution.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
+ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
+ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

src/libreadline/Makefile

@@ -0,0 +1,19 @@
+TOPSRC		= $(shell cd ../..; pwd)
+include $(TOPSRC)/target.mk
+
+CFLAGS          += -O -Wall -Werror
+
+OBJS		= readline.o
+
+all:            ../libreadline.a
+
+../libreadline.a: ${OBJS}
+		@$(AR) cru $@ ${OBJS}
+		$(RANLIB) $@
+
+install: 	all readline.h history.h
+		install -d $(DESTDIR)/include/readline/
+		cp -p readline.h history.h $(DESTDIR)/include/readline/
+
+clean:
+		rm -f *~ *.o a.out ../libreadline*.a

src/libreadline/Makefile-unix

@@ -0,0 +1,11 @@
+CFLAGS += -Wall -Werror -Os -g
+
+example: readline.o example.o
+	$(CC) $(LDFLAGS) -o $@ readline.o example.o
+
+clean:
+	rm -rf *.o example example.dSYM history.txt
+
+###
+example.o: example.c readline.h history.h
+readline.o: readline.c readline.h history.h

src/libreadline/README

@@ -0,0 +1,87 @@
+Linenoise
+~~~~~~~~~
+A minimal, zero-config, BSD licensed, readline replacement used
+in Redis, MongoDB, and Android.
+
+  * Single and multi line editing mode with the usual key bindings implemented.
+  * History handling.
+  * Completion.
+  * About 1,100 lines of BSD license source code.
+  * Only uses a subset of VT100 escapes (ANSI.SYS compatible).
+
+
+Can a line editing library be 20k lines of code?
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+Line editing with some support for history is a really
+important feature for command line utilities. Instead of
+retyping almost the same stuff again and again it's just much
+better to hit the up arrow and edit on syntax errors, or in
+order to try a slightly different command. But apparently code
+dealing with terminals is some sort of Black Magic: readline is
+30k lines of code, libedit 20k. Is it reasonable to link small
+utilities to huge libraries just to get a minimal support for
+line editing?
+
+So what usually happens is either:
+
+  * Large programs with configure scripts disabling line editing
+    if readline is not present in the system, or not supporting it
+    at all since readline is GPL licensed and libedit (the BSD
+    clone) is not as known and available as readline is (Real world
+    example of this problem: Tclsh).
+
+  * Smaller programs not using a configure script not
+    supporting line editing at all (A problem we had with Redis-cli
+    for instance).
+
+The result is a pollution of binaries without line editing support.
+
+So I spent more or less two hours doing a reality check
+resulting in this little library: is it *really* needed for a
+line editing library to be 20k lines of code? Apparently not,
+it is possibe to get a very small, zero configuration, trivial
+to embed library, that solves the problem. Smaller programs
+will just include this, supporing line editing out of the box.
+Larger programs may use this little library or just checking
+with configure if readline/libedit is available and resorting
+to linenoise if not.
+
+
+Terminals, in 2010
+~~~~~~~~~~~~~~~~~~
+Apparently almost every terminal you can happen to use today
+has some kind of support for basic VT100 escape sequences. So I
+tried to write a lib using just very basic VT100 features. The
+resulting library appears to work everywhere I tried to use it,
+and now can work even on ANSI.SYS compatible terminals, since
+no VT220 specific sequences are used anymore.
+
+The library is currently about 1100 lines of code. In order to
+use it in your project just look at the *example.c* file in the
+source distribution, it is trivial. Linenoise is BSD code, so
+you can use both in free software and commercial software.
+
+
+Tested with...
+~~~~~~~~~~~~~~
+  * Linux text only console ($TERM = linux)
+  * Linux KDE terminal application ($TERM = xterm)
+  * Linux xterm ($TERM = xterm)
+  * Linux Buildroot ($TERM = vt100)
+  * Mac OS X iTerm ($TERM = xterm)
+  * Mac OS X default Terminal.app ($TERM = xterm)
+  * OpenBSD 4.5 through an OSX Terminal.app ($TERM = screen)
+  * IBM AIX 6.1
+  * FreeBSD xterm ($TERM = xterm)
+  * ANSI.SYS
+  * Emacs comint mode ($TERM = dumb)
+
+Please test it everywhere you can and report back!
+
+
+Let's push this forward!
+~~~~~~~~~~~~~~~~~~~~~~~~
+Patches should be provided in the respect of linenoise
+sensibility for small easy to understand code.
+
+Send feedbacks to antirez at gmail

src/libreadline/example.c

@@ -0,0 +1,53 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include "readline.h"
+#include "history.h"
+
+int main(int argc, char **argv) {
+    char *line;
+    char *prgname = argv[0];
+
+    /* Parse options, with --multiline we enable multi line editing. */
+    while(argc > 1) {
+        argc--;
+        argv++;
+        if (!strcmp(*argv,"--multiline")) {
+            readline_set_multiline(1);
+            printf("Multi-line mode enabled.\n");
+        } else if (!strcmp(*argv,"--keycodes")) {
+            readline_print_keycodes();
+            exit(0);
+        } else {
+            fprintf(stderr, "Usage: %s [--multiline] [--keycodes]\n", prgname);
+            exit(1);
+        }
+    }
+
+    /* Load history from file. The history file is just a plain text file
+     * where entries are separated by newlines. */
+    add_history("history.txt"); /* Load the history at startup */
+
+    /* Now this is the main loop of the typical readline-based application.
+     * The call to readline() will block as long as the user types something
+     * and presses enter.
+     *
+     * The typed string is returned as a malloc() allocated string by
+     * readline, so the user needs to free() it. */
+    while((line = readline("hello> ")) != NULL) {
+        /* Do something with the string. */
+        if (line[0] != '\0' && line[0] != '/') {
+            printf("echo: '%s'\n", line);
+            add_history(line); /* Add to the history. */
+            write_history("history.txt"); /* Save the history on disk. */
+        } else if (!strncmp(line,"/historylen",11)) {
+            /* The "/historylen" command will change the history len. */
+            int len = atoi(line+11);
+            history_set_length(len);
+        } else if (line[0] == '/') {
+            printf("Unrecognized command: %s\n", line);
+        }
+        free(line);
+    }
+    return 0;
+}

src/libreadline/history.h

@@ -0,0 +1,75 @@
+/*
+ * Guerrilla line editing library against the idea that a line editing lib
+ * needs to be 20,000 lines of C code.
+ *
+ * Based on linenoise.c with API modified for compatibility with
+ * traditional readline library.
+ *
+ * ------------------------------------------------------------------------
+ *
+ * Copyright (c) 2010-2014, Salvatore Sanfilippo <antirez at gmail dot com>
+ * Copyright (c) 2010-2013, Pieter Noordhuis <pcnoordhuis at gmail dot com>
+ * Copyright (c) 2015, Serge Vakulenko <serge at vak dot ru>
+ *
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *  *  Redistributions of source code must retain the above copyright
+ *     notice, this list of conditions and the following disclaimer.
+ *
+ *  *  Redistributions in binary form must reproduce the above copyright
+ *     notice, this list of conditions and the following disclaimer in the
+ *     documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+#ifndef __HISTORY_H
+#define __HISTORY_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/*
+ * Place STRING at the end of the history list.
+ * The associated data field (if any) is set to NULL.
+ */
+void add_history(const char *line);
+
+/*
+ * Set the maximum length of the current history array.
+ */
+int history_set_length(int len);
+
+/*
+ * Add the contents of FILENAME to the history list, a line at a time.
+ * If FILENAME is NULL, then read from ~/.history.  Returns 0 if
+ * successful, or errno if not.
+ */
+int read_history(const char *filename);
+
+/*
+ * Write the current history to FILENAME.  If FILENAME is NULL,
+ * then write the history list to ~/.history.  Values returned
+ * are as in read_history ().
+ */
+int write_history(const char *filename);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* __HISTORY_H */

src/libreadline/readline.h

@@ -0,0 +1,74 @@
+/*
+ * Guerrilla line editing library against the idea that a line editing lib
+ * needs to be 20,000 lines of C code.
+ *
+ * Based on linenoise.c with API modified for compatibility with
+ * traditional readline library.
+ *
+ * ------------------------------------------------------------------------
+ *
+ * Copyright (c) 2010-2014, Salvatore Sanfilippo <antirez at gmail dot com>
+ * Copyright (c) 2010-2013, Pieter Noordhuis <pcnoordhuis at gmail dot com>
+ * Copyright (c) 2015, Serge Vakulenko <serge at vak dot ru>
+ *
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *  *  Redistributions of source code must retain the above copyright
+ *     notice, this list of conditions and the following disclaimer.
+ *
+ *  *  Redistributions in binary form must reproduce the above copyright
+ *     notice, this list of conditions and the following disclaimer in the
+ *     documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+#ifndef __READLINE_H
+#define __READLINE_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/*
+ * Read a line of input.
+ * Prompt with PROMPT.
+ * A NULL PROMPT means none.
+ */
+char *readline(const char *prompt);
+
+/*
+ * Clear the screen.
+ * Used to handle Ctrl+L.
+ */
+void readline_clear_screen(void);
+
+/*
+ * Set if to use or not the multi line mode.
+ */
+void readline_set_multiline(int ml);
+
+/*
+ * This routine is used in order to print scan codes on screen
+ * for debugging / development purposes.
+ */
+void readline_print_keycodes(void);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* __READLINE_H */