extern void bb_xprint_and_close_file(FILE *file)
{
bb_xfflush_stdout();
/* Note: Do not use STDOUT_FILENO here, as this is a lib routine
* and the calling code may have reassigned stdout. */
if (bb_copyfd_eof(fileno(file), STDOUT_FILENO) == -1) {
/* bb_copyfd outputs any needed messages, so just die. */
exit(bb_default_error_retval);
}
/* Note: Since we're reading, don't bother checking the return value
* of fclose(). The only possible failure is EINTR which
* should already have been taken care of. */
fclose(file);
}
int cmp_main(int argc, char **argv)
{
FILE *fp1, *fp2, *outfile = stdout;
const char *filename1, *filename2;
const char *fmt;
int c1, c2, char_pos, line_pos;
int opt_flags;
int exit_val = 0;
bb_default_error_retval = 2; /* 1 is returned if files are different. */
opt_flags = bb_getopt_ulflags(argc, argv, opt_chars);
if ((opt_flags == 3) || (((unsigned int)(--argc - optind)) > 1)) {
bb_show_usage();
}
fp1 = cmp_xfopen_input(filename1 = *(argv += optind));
filename2 = "-";
if (*++argv) {
filename2 = *argv;
}
fp2 = cmp_xfopen_input(filename2);
if (fp1 == fp2) { /* Paranioa check... stdin == stdin? */
/* Note that we don't bother reading stdin. Neither does gnu wc.
* But perhaps we should, so that other apps down the chain don't
* get the input. Consider 'echo hello | (cmp - - && cat -)'.
*/
return 0;
}
fmt = fmt_differ;
if (opt_flags == OPT_l) {
fmt = fmt_l_opt;
}
char_pos = 0;
line_pos = 1;
do {
c1 = getc(fp1);
c2 = getc(fp2);
++char_pos;
if (c1 != c2) { /* Remember -- a read error may have occurred. */
exit_val = 1; /* But assume the files are different for now. */
if (c2 == EOF) {
/* We know that fp1 isn't at EOF or in an error state. But to
* save space below, things are setup to expect an EOF in fp1
* if an EOF occurred. So, swap things around.
*/
fp1 = fp2;
filename1 = filename2;
c1 = c2;
}
if (c1 == EOF) {
bb_xferror(fp1, filename1);
fmt = fmt_eof; /* Well, no error, so it must really be EOF. */
outfile = stderr;
/* There may have been output to stdout (option -l), so
* make sure we fflush before writing to stderr. */
bb_xfflush_stdout();
}
if (opt_flags != OPT_s) {
if (opt_flags == OPT_l) {
line_pos = c1; /* line_pos is unused in the -l case. */
}
bb_fprintf(outfile, fmt, filename1, filename2, char_pos, line_pos, c2);
if (opt_flags) { /* This must be -l since not -s. */
/* If we encountered and EOF, the while check will catch it. */
continue;
}
}
break;
}
if (c1 == '\n') {
++line_pos;
}
} while (c1 != EOF);
bb_xferror(fp1, filename1);
bb_xferror(fp2, filename2);
bb_fflush_stdout_and_exit(exit_val);
}