129 lines
3.8 KiB
C
129 lines
3.8 KiB
C
#include <stdio.h>
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#include <errno.h>
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#include <fcntl.h>
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#include <unistd.h>
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int aaa;
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int bbb;
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int ccc;
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char gc;
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char gbuffer[3];
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int gibuffer[4];
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int main(void)
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{
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char b;
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int la;
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unsigned int u1, u2;
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int s1, s2;
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unsigned char uc1, uc2;
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char sc1, sc2;
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int fd;
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char buffer[6];
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int ibuffer[7];
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printf(" sizeof(uc1): %d 1\n", sizeof(uc1));
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printf(" sizeof(sc1): %d 1\n", sizeof(sc1));
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printf(" sizeof(u1): %d 4\n", sizeof(u1));
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printf(" sizeof(s1): %d 4\n", sizeof(s1));
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printf(" sizeof(aaa): %d 4\n", sizeof(aaa));
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printf(" sizeof(bbb): %d 4\n", sizeof(bbb));
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printf(" sizeof(gc): %d 1\n", sizeof(gc));
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printf(" sizeof(buffer): %d 6\n", sizeof(buffer));
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printf(" sizeof(ibuffer): %d 28\n", sizeof(ibuffer));
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printf(" sizeof(char): %d 1\n", sizeof(char));
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printf(" sizeof(int): %d 4\n", sizeof(int));
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printf(" sizeof(gbuffer): %d 3\n", sizeof(gbuffer));
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printf(" sizeof(gibuffer): %d 16\n", sizeof(gibuffer));
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// sizeof(ibuffer[0]) is not supported, so the following can be used...
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printf("sizeof(ibuffer)/sizeof(int): %d 7\n", sizeof(ibuffer)/sizeof(int));
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aaa = 1;
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bbb = 2;
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la = 4;
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printf("%d 1\n", aaa);
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printf("%d 2\n", bbb);
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printf("%d 4\n", la);
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uc1 = 0x80;
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sc1 = 0x80;
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s1 = uc1;
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s2 = sc1;
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printf("unsigned char (0x80) -> int: %d 128\n", s1);
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printf(" signed char (0x80) -> int: %d -128\n", s2);
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u1 = uc1;
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u2 = sc1;
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printf("unsigned char (0x80) -> unsigned: %d 128\n", u1);
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printf(" signed char (0x80) -> unsigned: %d -128\n", u2);
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la = errno;
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printf("errno: %d 0\n", la);
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write(1, "abcd ", 5);
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la = errno;
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printf("errno after good write call: %d 0\n", la);
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write(10, "abcde", 5);
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la = errno;
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printf("errno after bad write call: %d 9\n", la);
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write(1, "abcd ", 5);
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la = errno;
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printf("good write after failed should not overwrite errno: %d 9\n", la);
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errno = 0;
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write(1, "abcd ", 5);
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la = errno;
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printf("good write after errno set to zero: %d 0\n", la);
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la = write(1, "abcd ", 5);
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printf("write() return: %d 5\n", la);
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la = write(10, "abcd ", 5);
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printf("write(bad fd) return: %d -1\n", la);
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fd = open("/a.txt", O_WRONLY | O_CREAT, 0666);
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if (fd != -1) {
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printf("open success\n");
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la = write(fd, "abcd\n", 5);
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if (la == 5) printf("write success\n"); else printf("write failed\n");
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la = close(fd);
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if (la != -1) printf("close success\n"); else printf("close failed\n");
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} else {
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printf("open failed\n");
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}
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buffer[0] = 0;
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buffer[1] = 0;
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buffer[2] = 0;
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buffer[3] = 0;
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buffer[4] = 0;
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buffer[5] = 0;
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fd = open("/a.txt", O_RDONLY, 0666);
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if (fd != -1) {
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printf("open success\n");
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la = read(fd, buffer, 5);
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printf(buffer);
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if (la == 5) printf("read success\n"); else printf("read failed\n");
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la = close(fd);
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if (la != -1) printf("close success\n"); else printf("close failed\n");
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} else {
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printf("open failed\n");
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}
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if (buffer[0] != 'a') printf("data0 readback from file MISMATCH\n");
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if (buffer[1] != 'b') printf("data1 readback from file MISMATCH\n");
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if (buffer[2] != 'c') printf("data2 readback from file MISMATCH\n");
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if (buffer[3] != 'd') printf("data3 readback from file MISMATCH\n");
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if (buffer[4] != '\n') printf("data4 readback from file MISMATCH\n");
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if (buffer[0] != 'a' || buffer[1] != 'b' || buffer[2] != 'c' ||
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buffer[3] != 'd' || buffer[4] != '\n') {
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printf("data readback from file MISMATCH\n");
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} else {
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printf("data readback from file OK\n");
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}
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}
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