cmp: support 3rd and 4th arguments if DESKTOP=y (needed for gcc build)

2 files changed, 29 insertions, 12 deletions

diff --git a/coreutils/cmp.c b/coreutils/cmp.c
index 0aebd4b4d..cff118279 100644
--- a/coreutils/cmp.c
+++ b/coreutils/cmp.c
@@ -34,9 +34,9 @@ static FILE *cmp_xfopen_input(const char * const filename)
 }
 
 static const char fmt_eof[] = "cmp: EOF on %s\n";
-static const char fmt_differ[] = "%s %s differ: char %d, line %d\n";
-// This fmt_l_opt uses gnu-isms.  SUSv3 would be "%.0s%.0s%d %o %o\n"
-static const char fmt_l_opt[] = "%.0s%.0s%d %3o %3o\n";
+static const char fmt_differ[] = "%s %s differ: char %"OFF_FMT"d, line %d\n";
+// This fmt_l_opt uses gnu-isms.  SUSv3 would be "%.0s%.0s%"OFF_FMT"d %o %o\n"
+static const char fmt_l_opt[] = "%.0s%.0s%"OFF_FMT"d %3o %3o\n";
 
 static const char opt_chars[] = "sl";
 #define CMP_OPT_s (1<<0)
@@ -47,27 +47,40 @@ int cmp_main(int argc, char **argv)
 {
         FILE *fp1, *fp2, *outfile = stdout;
         const char *filename1, *filename2 = "-";
+        USE_DESKTOP(off_t skip1 = 0, skip2 = 0;)
+        off_t char_pos = 0;
+        int line_pos = 1; /* Hopefully won't overflow... */
         const char *fmt;
-        int c1, c2, char_pos = 0, line_pos = 1;
+        int c1, c2;
         unsigned opt;
         int retval = 0;
 
         xfunc_error_retval = 2; /* 1 is returned if files are different. */
 
+        opt_complementary = "?:-1"
+                        USE_DESKTOP(":?4")
+                        SKIP_DESKTOP(":?2")
+                        ":l--s:s--l";
         opt = getopt32(argc, argv, opt_chars);
+        argv += optind;
 
-        if (((opt & (CMP_OPT_s|CMP_OPT_l)) == (CMP_OPT_s|CMP_OPT_l))
-                        || (((unsigned int)(--argc - optind)) > 1))
-                bb_show_usage();
-
-        fp1 = cmp_xfopen_input(filename1 = *(argv += optind));
+        filename1 = *argv;
+        fp1 = cmp_xfopen_input(filename1);
 
         if (*++argv) {
                 filename2 = *argv;
+#if ENABLE_DESKTOP
+                if (*++argv) {
+                        skip1 = XATOOFF(*argv);
+                        if (*++argv) {
+                                skip2 = XATOOFF(*argv);
+                        }
+                }
+#endif
         }
-        fp2 = cmp_xfopen_input(filename2);
 
-        if (fp1 == fp2) {                       /* Paranioa check... stdin == stdin? */
+        fp2 = cmp_xfopen_input(filename2);
+        if (fp1 == fp2) {               /* Paranoia 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 -)'.
@@ -80,6 +93,10 @@ int cmp_main(int argc, char **argv)
         else
                 fmt = fmt_differ;
 
+#if ENABLE_DESKTOP
+        while (skip1) { getc(fp1); skip1--; }
+        while (skip2) { getc(fp2); skip2--; }
+#endif
         do {
                 c1 = getc(fp1);
                 c2 = getc(fp2);
diff --git a/include/usage.h b/include/usage.h
index db38504b8..66f8638f5 100644
--- a/include/usage.h
+++ b/include/usage.h
@@ -377,7 +377,7 @@
        "Clear screen"
 
 #define cmp_trivial_usage \
-       "[-l] [-s] FILE1 [FILE2]"
+       "[-l] [-s] FILE1 [FILE2" USE_DESKTOP(" [SKIP1 [SKIP2]") "]]"
 #define cmp_full_usage \
        "Compares FILE1 vs stdin if FILE2 is not specified" \
        "\n\nOptions:\n" \