builtin-cat-file.c

   1 /*
   2  * GIT - The information manager from hell
   3  *
   4  * Copyright (C) Linus Torvalds, 2005
   5  */
   6 #include "cache.h"
   7 #include "exec_cmd.h"
   8 #include "tag.h"
   9 #include "tree.h"
  10 #include "builtin.h"
  11
  12 static void flush_buffer(const char *buf, unsigned long size)
  13 {
  14         while (size > 0) {
  15                 long ret = xwrite(1, buf, size);
  16                 if (ret < 0) {
  17                         /* Ignore epipe */
  18                         if (errno == EPIPE)
  19                                 break;
  20                         die("git-cat-file: %s", strerror(errno));
  21                 } else if (!ret) {
  22                         die("git-cat-file: disk full?");
  23                 }
  24                 size -= ret;
  25                 buf += ret;
  26         }
  27 }
  28
  29 static int pprint_tag(const unsigned char *sha1, const char *buf, unsigned long size)
  30 {
  31         /* the parser in tag.c is useless here. */
  32         const char *endp = buf + size;
  33         const char *cp = buf;
  34
  35         while (cp < endp) {
  36                 char c = *cp++;
  37                 if (c != '\n')
  38                         continue;
  39                 if (7 <= endp - cp && !memcmp("tagger ", cp, 7)) {
  40                         const char *tagger = cp;
  41
  42                         /* Found the tagger line.  Copy out the contents
  43                          * of the buffer so far.
  44                          */
  45                         flush_buffer(buf, cp - buf);
  46
  47                         /*
  48                          * Do something intelligent, like pretty-printing
  49                          * the date.
  50                          */
  51                         while (cp < endp) {
  52                                 if (*cp++ == '\n') {
  53                                         /* tagger to cp is a line
  54                                          * that has ident and time.
  55                                          */
  56                                         const char *sp = tagger;
  57                                         char *ep;
  58                                         unsigned long date;
  59                                         long tz;
  60                                         while (sp < cp && *sp != '>')
  61                                                 sp++;
  62                                         if (sp == cp) {
  63                                                 /* give up */
  64                                                 flush_buffer(tagger,
  65                                                              cp - tagger);
  66                                                 break;
  67                                         }
  68                                         while (sp < cp &&
  69                                                !('0' <= *sp && *sp <= '9'))
  70                                                 sp++;
  71                                         flush_buffer(tagger, sp - tagger);
  72                                         date = strtoul(sp, &ep, 10);
  73                                         tz = strtol(ep, NULL, 10);
  74                                         sp = show_date(date, tz);
  75                                         flush_buffer(sp, strlen(sp));
  76                                         xwrite(1, "\n", 1);
  77                                         break;
  78                                 }
  79                         }
  80                         break;
  81                 }
  82                 if (cp < endp && *cp == '\n')
  83                         /* end of header */
  84                         break;
  85         }
  86         /* At this point, we have copied out the header up to the end of
  87          * the tagger line and cp points at one past \n.  It could be the
  88          * next header line after the tagger line, or it could be another
  89          * \n that marks the end of the headers.  We need to copy out the
  90          * remainder as is.
  91          */
  92         if (cp < endp)
  93                 flush_buffer(cp, endp - cp);
  94         return 0;
  95 }
  96
  97 int cmd_cat_file(int argc, const char **argv, const char *prefix)
  98 {
  99         unsigned char sha1[20];
 100         char type[20];
 101         void *buf;
 102         unsigned long size;
 103         int opt;
 104
 105         git_config(git_default_config);
 106         if (argc != 3)
 107                 usage("git-cat-file [-t|-s|-e|-p|<type>] <sha1>");
 108         if (get_sha1(argv[2], sha1))
 109                 die("Not a valid object name %s", argv[2]);
 110
 111         opt = 0;
 112         if ( argv[1][0] == '-' ) {
 113                 opt = argv[1][1];
 114                 if ( !opt || argv[1][2] )
 115                         opt = -1; /* Not a single character option */
 116         }
 117
 118         buf = NULL;
 119         switch (opt) {
 120         case 't':
 121                 if (!sha1_object_info(sha1, type, NULL)) {
 122                         printf("%s\n", type);
 123                         return 0;
 124                 }
 125                 break;
 126
 127         case 's':
 128                 if (!sha1_object_info(sha1, type, &size)) {
 129                         printf("%lu\n", size);
 130                         return 0;
 131                 }
 132                 break;
 133
 134         case 'e':
 135                 return !has_sha1_file(sha1);
 136
 137         case 'p':
 138                 if (sha1_object_info(sha1, type, NULL))
 139                         die("Not a valid object name %s", argv[2]);
 140
 141                 /* custom pretty-print here */
 142                 if (!strcmp(type, tree_type))
 143                         return cmd_ls_tree(2, argv + 1, NULL);
 144
 145                 buf = read_sha1_file(sha1, type, &size);
 146                 if (!buf)
 147                         die("Cannot read object %s", argv[2]);
 148                 if (!strcmp(type, tag_type))
 149                         return pprint_tag(sha1, buf, size);
 150
 151                 /* otherwise just spit out the data */
 152                 break;
 153         case 0:
 154                 buf = read_object_with_reference(sha1, argv[1], &size, NULL);
 155                 break;
 156
 157         default:
 158                 die("git-cat-file: unknown option: %s\n", argv[1]);
 159         }
 160
 161         if (!buf)
 162                 die("git-cat-file %s: bad file", argv[2]);
 163
 164         flush_buffer(buf, size);
 165         return 0;
 166 }