#include #include #define TESTFILE "/tmp/test.dat" int main __P((void)) { FILE *fp; int i, j; puts ("\nFile seek test"); fp = fopen (TESTFILE, "w"); if (fp == NULL) { perror (TESTFILE); return 1; } for (i = 0; i < 256; i++) putc (i, fp); if (freopen (TESTFILE, "r", fp) != fp) { perror ("Cannot open file for reading"); return 1; } for (i = 1; i <= 255; i++) { printf ("%3d\n", i); fseek (fp, (long) -i, SEEK_END); if ((j = getc (fp)) != 256 - i) { printf ("SEEK_END failed %d\n", j); break; } if (fseek (fp, (long) i, SEEK_SET)) { puts ("Cannot SEEK_SET"); break; } if ((j = getc (fp)) != i) { printf ("SEEK_SET failed %d\n", j); break; } if (fseek (fp, (long) i, SEEK_SET)) { puts ("Cannot SEEK_SET"); break; } if (fseek (fp, (long) (i >= 128 ? -128 : 128), SEEK_CUR)) { puts ("Cannot SEEK_CUR"); break; } if ((j = getc (fp)) != (i >= 128 ? i - 128 : i + 128)) { printf ("SEEK_CUR failed %d\n", j); break; } } fclose (fp); puts ((i > 255) ? "Test succeeded." : "Test FAILED!"); return (i > 255) ? 0 : 1; }