Andrew's git / gitweb.git / git.c
?
git.con commit apply: allow-binary-replacement. (011f427)
   1#include <stdio.h>
   2#include <sys/types.h>
   3#include <sys/stat.h>
   4#include <dirent.h>
   5#include <unistd.h>
   6#include <stdlib.h>
   7#include <string.h>
   8#include <errno.h>
   9#include <limits.h>
  10#include <stdarg.h>
  11
  12#ifndef PATH_MAX
  13# define PATH_MAX 4096
  14#endif
  15
  16static const char git_usage[] =
  17        "Usage: git [--version] [--exec-path[=GIT_EXEC_PATH]] [--help] COMMAND [ ARGS ]";
  18
  19/* most gui terms set COLUMNS (although some don't export it) */
  20static int term_columns(void)
  21{
  22        char *col_string = getenv("COLUMNS");
  23        int n_cols = 0;
  24
  25        if (col_string && (n_cols = atoi(col_string)) > 0)
  26                return n_cols;
  27
  28        return 80;
  29}
  30
  31static void oom(void)
  32{
  33        fprintf(stderr, "git: out of memory\n");
  34        exit(1);
  35}
  36
  37static inline void mput_char(char c, unsigned int num)
  38{
  39        while(num--)
  40                putchar(c);
  41}
  42
  43static struct cmdname {
  44        size_t len;
  45        char name[1];
  46} **cmdname;
  47static int cmdname_alloc, cmdname_cnt;
  48
  49static void add_cmdname(const char *name, int len)
  50{
  51        struct cmdname *ent;
  52        if (cmdname_alloc <= cmdname_cnt) {
  53                cmdname_alloc = cmdname_alloc + 200;
  54                cmdname = realloc(cmdname, cmdname_alloc * sizeof(*cmdname));
  55                if (!cmdname)
  56                        oom();
  57        }
  58        ent = malloc(sizeof(*ent) + len);
  59        if (!ent)
  60                oom();
  61        ent->len = len;
  62        memcpy(ent->name, name, len+1);
  63        cmdname[cmdname_cnt++] = ent;
  64}
  65
  66static int cmdname_compare(const void *a_, const void *b_)
  67{
  68        struct cmdname *a = *(struct cmdname **)a_;
  69        struct cmdname *b = *(struct cmdname **)b_;
  70        return strcmp(a->name, b->name);
  71}
  72
  73static void pretty_print_string_list(struct cmdname **cmdname, int longest)
  74{
  75        int cols = 1;
  76        int space = longest + 1; /* min 1 SP between words */
  77        int max_cols = term_columns() - 1; /* don't print *on* the edge */
  78        int i;
  79
  80        if (space < max_cols)
  81                cols = max_cols / space;
  82
  83        qsort(cmdname, cmdname_cnt, sizeof(*cmdname), cmdname_compare);
  84
  85        for (i = 0; i < cmdname_cnt; ) {
  86                int c;
  87                printf("  ");
  88
  89                for (c = cols; c && i < cmdname_cnt; i++) {
  90                        printf("%s", cmdname[i]->name);
  91
  92                        if (--c)
  93                                mput_char(' ', space - cmdname[i]->len);
  94                }
  95                putchar('\n');
  96        }
  97}
  98
  99static void list_commands(const char *exec_path, const char *pattern)
 100{
 101        unsigned int longest = 0;
 102        char path[PATH_MAX];
 103        int dirlen;
 104        DIR *dir = opendir(exec_path);
 105        struct dirent *de;
 106
 107        if (!dir) {
 108                fprintf(stderr, "git: '%s': %s\n", exec_path, strerror(errno));
 109                exit(1);
 110        }
 111
 112        dirlen = strlen(exec_path);
 113        if (PATH_MAX - 20 < dirlen) {
 114                fprintf(stderr, "git: insanely long exec-path '%s'\n",
 115                        exec_path);
 116                exit(1);
 117        }
 118
 119        memcpy(path, exec_path, dirlen);
 120        path[dirlen++] = '/';
 121
 122        while ((de = readdir(dir)) != NULL) {
 123                struct stat st;
 124                int entlen;
 125
 126                if (strncmp(de->d_name, "git-", 4))
 127                        continue;
 128                strcpy(path+dirlen, de->d_name);
 129                if (stat(path, &st) || /* stat, not lstat */
 130                    !S_ISREG(st.st_mode) ||
 131                    !(st.st_mode & S_IXUSR))
 132                        continue;
 133
 134                entlen = strlen(de->d_name);
 135
 136                if (longest < entlen)
 137                        longest = entlen;
 138
 139                add_cmdname(de->d_name + 4, entlen-4);
 140        }
 141        closedir(dir);
 142
 143        printf("git commands available in '%s'\n", exec_path);
 144        printf("----------------------------");
 145        mput_char('-', strlen(exec_path));
 146        putchar('\n');
 147        pretty_print_string_list(cmdname, longest - 4);
 148        putchar('\n');
 149}
 150
 151#ifdef __GNUC__
 152static void usage(const char *exec_path, const char *fmt, ...)
 153        __attribute__((__format__(__printf__, 2, 3), __noreturn__));
 154#endif
 155static void usage(const char *exec_path, const char *fmt, ...)
 156{
 157        if (fmt) {
 158                va_list ap;
 159
 160                va_start(ap, fmt);
 161                printf("git: ");
 162                vprintf(fmt, ap);
 163                va_end(ap);
 164                putchar('\n');
 165        }
 166        else
 167                puts(git_usage);
 168
 169        putchar('\n');
 170
 171        if(exec_path)
 172                list_commands(exec_path, "git-*");
 173
 174        exit(1);
 175}
 176
 177static void prepend_to_path(const char *dir, int len)
 178{
 179        char *path, *old_path = getenv("PATH");
 180        int path_len = len;
 181
 182        if (!old_path)
 183                old_path = "/usr/local/bin:/usr/bin:/bin";
 184
 185        path_len = len + strlen(old_path) + 1;
 186
 187        path = malloc(path_len + 1);
 188        path[path_len + 1] = '\0';
 189
 190        memcpy(path, dir, len);
 191        path[len] = ':';
 192        memcpy(path + len + 1, old_path, path_len - len);
 193
 194        setenv("PATH", path, 1);
 195}
 196
 197static void show_man_page(char *git_cmd)
 198{
 199        char *page;
 200
 201        if (!strncmp(git_cmd, "git", 3))
 202                page = git_cmd;
 203        else {
 204                int page_len = strlen(git_cmd) + 4;
 205
 206                page = malloc(page_len + 1);
 207                strcpy(page, "git-");
 208                strcpy(page + 4, git_cmd);
 209                page[page_len] = 0;
 210        }
 211
 212        execlp("man", "man", page, NULL);
 213}
 214
 215int main(int argc, char **argv, char **envp)
 216{
 217        char git_command[PATH_MAX + 1];
 218        char wd[PATH_MAX + 1];
 219        int i, len, show_help = 0;
 220        char *exec_path = getenv("GIT_EXEC_PATH");
 221
 222        getcwd(wd, PATH_MAX);
 223
 224        if (!exec_path)
 225                exec_path = GIT_EXEC_PATH;
 226
 227        for (i = 1; i < argc; i++) {
 228                char *arg = argv[i];
 229
 230                if (strncmp(arg, "--", 2))
 231                        break;
 232
 233                arg += 2;
 234
 235                if (!strncmp(arg, "exec-path", 9)) {
 236                        arg += 9;
 237                        if (*arg == '=')
 238                                exec_path = arg + 1;
 239                        else {
 240                                puts(exec_path);
 241                                exit(0);
 242                        }
 243                }
 244                else if (!strcmp(arg, "version")) {
 245                        printf("git version %s\n", GIT_VERSION);
 246                        exit(0);
 247                }
 248                else if (!strcmp(arg, "help"))
 249                        show_help = 1;
 250                else if (!show_help)
 251                        usage(NULL, NULL);
 252        }
 253
 254        if (i >= argc || show_help) {
 255                if (i >= argc)
 256                        usage(exec_path, NULL);
 257
 258                show_man_page(argv[i]);
 259        }
 260
 261        if (*exec_path != '/') {
 262                if (!getcwd(git_command, sizeof(git_command))) {
 263                        fprintf(stderr,
 264                                "git: cannot determine current directory");
 265                        exit(1);
 266                }
 267                len = strlen(git_command);
 268
 269                /* Trivial cleanup */
 270                while (!strncmp(exec_path, "./", 2)) {
 271                        exec_path += 2;
 272                        while (*exec_path == '/')
 273                                *exec_path++;
 274                }
 275                snprintf(git_command + len, sizeof(git_command) - len,
 276                         "/%s", exec_path);
 277        }
 278        else
 279                strcpy(git_command, exec_path);
 280        len = strlen(git_command);
 281        prepend_to_path(git_command, len);
 282
 283        strncat(&git_command[len], "/git-", sizeof(git_command) - len);
 284        len += 5;
 285        strncat(&git_command[len], argv[i], sizeof(git_command) - len);
 286
 287        if (access(git_command, X_OK))
 288                usage(exec_path, "'%s' is not a git-command", argv[i]);
 289
 290        /* execve() can only ever return if it fails */
 291        execve(git_command, &argv[i], envp);
 292        printf("Failed to run command '%s': %s\n", git_command, strerror(errno));
 293
 294        return 1;
 295}