show-diff.c

   1 /*
   2  * GIT - The information manager from hell
   3  *
   4  * Copyright (C) Linus Torvalds, 2005
   5  */
   6 #include "cache.h"
   7
   8 static void show_differences(char *name,
   9         void *old_contents, unsigned long long old_size)
  10 {
  11         static char cmd[1000];
  12         FILE *f;
  13
  14         snprintf(cmd, sizeof(cmd), "diff -L %s -u -N  - %s", name, name);
  15         f = popen(cmd, "w");
  16         if (old_size)
  17                 fwrite(old_contents, old_size, 1, f);
  18         pclose(f);
  19 }
  20
  21 static void show_diff_empty(struct cache_entry *ce)
  22 {
  23         char *old;
  24         unsigned long int size;
  25         int lines=0;
  26         unsigned char type[20], *p, *end;
  27
  28         old = read_sha1_file(ce->sha1, type, &size);
  29         if (size > 0) {
  30                 int startline = 1;
  31                 int c = 0;
  32
  33                 printf("--- %s\n", ce->name);
  34                 printf("+++ /dev/null\n");
  35                 p = old;
  36                 end = old + size;
  37                 while (p < end)
  38                         if (*p++ == '\n')
  39                                 lines ++;
  40                 printf("@@ -1,%d +0,0 @@\n", lines);
  41                 p = old;
  42                 while (p < end) {
  43                         c = *p++;
  44                         if (startline) {
  45                                 putchar('-');
  46                                 startline = 0;
  47                         }
  48                         putchar(c);
  49                         if (c == '\n')
  50                                 startline = 1;
  51                 }
  52                 if (c!='\n')
  53                         printf("\n");
  54                 fflush(stdout);
  55         }
  56 }
  57
  58 static const char *show_diff_usage = "show-diff [-s] [-q] [paths...]";
  59
  60 static int matches_pathspec(struct cache_entry *ce, char **spec, int cnt)
  61 {
  62         int i;
  63         int namelen = ce_namelen(ce);
  64         for (i = 0; i < cnt; i++) {
  65                 int speclen = strlen(spec[i]);
  66                 if (! strncmp(spec[i], ce->name, speclen) &&
  67                     speclen <= namelen &&
  68                     (ce->name[speclen] == 0 ||
  69                      ce->name[speclen] == '/'))
  70                         return 1;
  71         }
  72         return 0;
  73 }
  74
  75 int main(int argc, char **argv)
  76 {
  77         int silent = 0;
  78         int silent_on_nonexisting_files = 0;
  79         int entries = read_cache();
  80         int i;
  81
  82         while (1 < argc && argv[1][0] == '-') {
  83                 if (!strcmp(argv[1], "-s"))
  84                         silent_on_nonexisting_files = silent = 1;
  85                 else if (!strcmp(argv[1], "-q"))
  86                         silent_on_nonexisting_files = 1;
  87                 else
  88                         usage(show_diff_usage);
  89                 argv++; argc--;
  90         }
  91
  92         /* At this point, if argc == 1, then we are doing everything.
  93          * Otherwise argv[1] .. argv[argc-1] have the explicit paths.
  94          */
  95         if (entries < 0) {
  96                 perror("read_cache");
  97                 exit(1);
  98         }
  99         for (i = 0; i < entries; i++) {
 100                 struct stat st;
 101                 struct cache_entry *ce = active_cache[i];
 102                 int n, changed;
 103                 unsigned long size;
 104                 char type[20];
 105                 void *new;
 106
 107                 if (1 <argc &&
 108                     ! matches_pathspec(ce, argv+1, argc-1))
 109                         continue;
 110
 111                 if (stat(ce->name, &st) < 0) {
 112                         if (errno == ENOENT && silent_on_nonexisting_files)
 113                                 continue;
 114                         printf("%s: %s\n", ce->name, strerror(errno));
 115                         if (errno == ENOENT)
 116                                 show_diff_empty(ce);
 117                         continue;
 118                 }
 119                 changed = cache_match_stat(ce, &st);
 120                 if (!changed)
 121                         continue;
 122                 printf("%s:  ", ce->name);
 123                 for (n = 0; n < 20; n++)
 124                         printf("%02x", ce->sha1[n]);
 125                 printf("\n");
 126                 fflush(stdout);
 127                 if (silent)
 128                         continue;
 129
 130                 new = read_sha1_file(ce->sha1, type, &size);
 131                 show_differences(ce->name, new, size);
 132                 free(new);
 133         }
 134         return 0;
 135 }