ls-tree.c

   1 /*
   2  * GIT - The information manager from hell
   3  *
   4  * Copyright (C) Linus Torvalds, 2005
   5  */
   6 #include "cache.h"
   7 #include "blob.h"
   8 #include "tree.h"
   9 #include "quote.h"
  10
  11 static int line_termination = '\n';
  12 #define LS_RECURSIVE 1
  13 #define LS_TREE_ONLY 2
  14 static int ls_options = 0;
  15
  16 static struct tree_entry_list root_entry;
  17
  18 static void prepare_root(unsigned char *sha1)
  19 {
  20         unsigned char rsha[20];
  21         unsigned long size;
  22         void *buf;
  23         struct tree *root_tree;
  24
  25         buf = read_object_with_reference(sha1, "tree", &size, rsha);
  26         free(buf);
  27         if (!buf)
  28                 die("Could not read %s", sha1_to_hex(sha1));
  29
  30         root_tree = lookup_tree(rsha);
  31         if (!root_tree)
  32                 die("Could not read %s", sha1_to_hex(sha1));
  33
  34         /* Prepare a fake entry */
  35         root_entry.directory = 1;
  36         root_entry.executable = root_entry.symlink = 0;
  37         root_entry.mode = S_IFDIR;
  38         root_entry.name = "";
  39         root_entry.item.tree = root_tree;
  40         root_entry.parent = NULL;
  41 }
  42
  43 static int prepare_children(struct tree_entry_list *elem)
  44 {
  45         if (!elem->directory)
  46                 return -1;
  47         if (!elem->item.tree->object.parsed) {
  48                 struct tree_entry_list *e;
  49                 if (parse_tree(elem->item.tree))
  50                         return -1;
  51                 /* Set up the parent link */
  52                 for (e = elem->item.tree->entries; e; e = e->next)
  53                         e->parent = elem;
  54         }
  55         return 0;
  56 }
  57
  58 static struct tree_entry_list *find_entry(const char *path, char *pathbuf)
  59 {
  60         const char *next, *slash;
  61         int len;
  62         struct tree_entry_list *elem = &root_entry, *oldelem = NULL;
  63
  64         *(pathbuf) = '\0';
  65
  66         /* Find tree element, descending from root, that
  67          * corresponds to the named path, lazily expanding
  68          * the tree if possible.
  69          */
  70
  71         while (path) {
  72                 /* The fact we still have path means that the caller
  73                  * wants us to make sure that elem at this point is a
  74                  * directory, and possibly descend into it.  Even what
  75                  * is left is just trailing slashes, we loop back to
  76                  * here, and this call to prepare_children() will
  77                  * catch elem not being a tree.  Nice.
  78                  */
  79                 if (prepare_children(elem))
  80                         return NULL;
  81
  82                 slash = strchr(path, '/');
  83                 if (!slash) {
  84                         len = strlen(path);
  85                         next = NULL;
  86                 }
  87                 else {
  88                         next = slash + 1;
  89                         len = slash - path;
  90                 }
  91                 if (len) {
  92                         if (oldelem) {
  93                                 pathbuf += sprintf(pathbuf, "%s/", oldelem->name);
  94                         }
  95
  96                         /* (len == 0) if the original path was "drivers/char/"
  97                          * and we have run already two rounds, having elem
  98                          * pointing at the drivers/char directory.
  99                          */
 100                         elem = elem->item.tree->entries;
 101                         while (elem) {
 102                                 if ((strlen(elem->name) == len) &&
 103                                     !strncmp(elem->name, path, len)) {
 104                                         /* found */
 105                                         break;
 106                                 }
 107                                 elem = elem->next;
 108                         }
 109                         if (!elem)
 110                                 return NULL;
 111
 112                         oldelem = elem;
 113                 }
 114                 path = next;
 115         }
 116
 117         return elem;
 118 }
 119
 120 static const char *entry_type(struct tree_entry_list *e)
 121 {
 122         return (e->directory ? "tree" : "blob");
 123 }
 124
 125 static const char *entry_hex(struct tree_entry_list *e)
 126 {
 127         return sha1_to_hex(e->directory
 128                            ? e->item.tree->object.sha1
 129                            : e->item.blob->object.sha1);
 130 }
 131
 132 /* forward declaration for mutually recursive routines */
 133 static int show_entry(struct tree_entry_list *, int, char *pathbuf);
 134
 135 static int show_children(struct tree_entry_list *e, int level, char *pathbuf)
 136 {
 137         int oldlen = strlen(pathbuf);
 138
 139         if (e != &root_entry)
 140                 sprintf(pathbuf + oldlen, "%s/", e->name);
 141
 142         if (prepare_children(e))
 143                 die("internal error: ls-tree show_children called with non tree");
 144         e = e->item.tree->entries;
 145         while (e) {
 146                 show_entry(e, level, pathbuf);
 147                 e = e->next;
 148         }
 149
 150         pathbuf[oldlen] = '\0';
 151
 152         return 0;
 153 }
 154
 155 static int show_entry(struct tree_entry_list *e, int level, char *pathbuf)
 156 {
 157         int err = 0;
 158
 159         if (e != &root_entry) {
 160                 printf("%06o %s %s      ",
 161                        e->mode, entry_type(e), entry_hex(e));
 162                 write_name_quoted(pathbuf, e->name, line_termination, stdout);
 163                 putchar(line_termination);
 164         }
 165
 166         if (e->directory) {
 167                 /* If this is a directory, we have the following cases:
 168                  * (1) This is the top-level request (explicit path from the
 169                  *     command line, or "root" if there is no command line).
 170                  *  a. Without any flag.  We show direct children.  We do not
 171                  *     recurse into them.
 172                  *  b. With -r.  We do recurse into children.
 173                  *  c. With -d.  We do not recurse into children.
 174                  * (2) We came here because our caller is either (1-a) or
 175                  *     (1-b).
 176                  *  a. Without any flag.  We do not show our children (which
 177                  *     are grandchildren for the original request).
 178                  *  b. With -r.  We continue to recurse into our children.
 179                  *  c. With -d.  We should not have come here to begin with.
 180                  */
 181                 if (level == 0 && !(ls_options & LS_TREE_ONLY))
 182                         /* case (1)-a and (1)-b */
 183                         err = err | show_children(e, level+1, pathbuf);
 184                 else if (level && ls_options & LS_RECURSIVE)
 185                         /* case (2)-b */
 186                         err = err | show_children(e, level+1, pathbuf);
 187         }
 188         return err;
 189 }
 190
 191 static int list_one(const char *path)
 192 {
 193         int err = 0;
 194         char pathbuf[MAXPATHLEN + 1];
 195         struct tree_entry_list *e = find_entry(path, pathbuf);
 196         if (!e) {
 197                 /* traditionally ls-tree does not complain about
 198                  * missing path.  We may change this later to match
 199                  * what "/bin/ls -a" does, which is to complain.
 200                  */
 201                 return err;
 202         }
 203         err = err | show_entry(e, 0, pathbuf);
 204         return err;
 205 }
 206
 207 static int list(char **path)
 208 {
 209         int i;
 210         int err = 0;
 211         for (i = 0; path[i]; i++)
 212                 err = err | list_one(path[i]);
 213         return err;
 214 }
 215
 216 static const char ls_tree_usage[] =
 217         "git-ls-tree [-d] [-r] [-z] <tree-ish> [path...]";
 218
 219 int main(int argc, char **argv)
 220 {
 221         static char *path0[] = { "", NULL };
 222         char **path;
 223         unsigned char sha1[20];
 224
 225         while (1 < argc && argv[1][0] == '-') {
 226                 switch (argv[1][1]) {
 227                 case 'z':
 228                         line_termination = 0;
 229                         break;
 230                 case 'r':
 231                         ls_options |= LS_RECURSIVE;
 232                         break;
 233                 case 'd':
 234                         ls_options |= LS_TREE_ONLY;
 235                         break;
 236                 default:
 237                         usage(ls_tree_usage);
 238                 }
 239                 argc--; argv++;
 240         }
 241
 242         if (argc < 2)
 243                 usage(ls_tree_usage);
 244         if (get_sha1(argv[1], sha1) < 0)
 245                 usage(ls_tree_usage);
 246
 247         path = (argc == 2) ? path0 : (argv + 2);
 248         prepare_root(sha1);
 249         if (list(path) < 0)
 250                 die("list failed");
 251         return 0;
 252 }