shell.con commit Documentation: simplify How Merge Works (ebef7e5)
   1#include "cache.h"
   2#include "quote.h"
   3#include "exec_cmd.h"
   4#include "strbuf.h"
   5
   6static int do_generic_cmd(const char *me, char *arg)
   7{
   8        const char *my_argv[4];
   9
  10        setup_path();
  11        if (!arg || !(arg = sq_dequote(arg)))
  12                die("bad argument");
  13        if (prefixcmp(me, "git-"))
  14                die("bad command");
  15
  16        my_argv[0] = me + 4;
  17        my_argv[1] = arg;
  18        my_argv[2] = NULL;
  19
  20        return execv_git_cmd(my_argv);
  21}
  22
  23static int do_cvs_cmd(const char *me, char *arg)
  24{
  25        const char *cvsserver_argv[3] = {
  26                "cvsserver", "server", NULL
  27        };
  28
  29        if (!arg || strcmp(arg, "server"))
  30                die("git-cvsserver only handles server: %s", arg);
  31
  32        setup_path();
  33        return execv_git_cmd(cvsserver_argv);
  34}
  35
  36
  37static struct commands {
  38        const char *name;
  39        int (*exec)(const char *me, char *arg);
  40} cmd_list[] = {
  41        { "git-receive-pack", do_generic_cmd },
  42        { "git-upload-pack", do_generic_cmd },
  43        { "git-upload-archive", do_generic_cmd },
  44        { "cvs", do_cvs_cmd },
  45        { NULL },
  46};
  47
  48int main(int argc, char **argv)
  49{
  50        char *prog;
  51        struct commands *cmd;
  52        int devnull_fd;
  53
  54        /*
  55         * Always open file descriptors 0/1/2 to avoid clobbering files
  56         * in die().  It also avoids not messing up when the pipes are
  57         * dup'ed onto stdin/stdout/stderr in the child processes we spawn.
  58         */
  59        devnull_fd = open("/dev/null", O_RDWR);
  60        while (devnull_fd >= 0 && devnull_fd <= 2)
  61                devnull_fd = dup(devnull_fd);
  62        if (devnull_fd == -1)
  63                die_errno("opening /dev/null failed");
  64        close (devnull_fd);
  65
  66        /*
  67         * Special hack to pretend to be a CVS server
  68         */
  69        if (argc == 2 && !strcmp(argv[1], "cvs server"))
  70                argv--;
  71
  72        /*
  73         * We do not accept anything but "-c" followed by "cmd arg",
  74         * where "cmd" is a very limited subset of git commands.
  75         */
  76        else if (argc != 3 || strcmp(argv[1], "-c"))
  77                die("What do you think I am? A shell?");
  78
  79        prog = argv[2];
  80        if (!strncmp(prog, "git", 3) && isspace(prog[3]))
  81                /* Accept "git foo" as if the caller said "git-foo". */
  82                prog[3] = '-';
  83
  84        for (cmd = cmd_list ; cmd->name ; cmd++) {
  85                int len = strlen(cmd->name);
  86                char *arg;
  87                if (strncmp(cmd->name, prog, len))
  88                        continue;
  89                arg = NULL;
  90                switch (prog[len]) {
  91                case '\0':
  92                        arg = NULL;
  93                        break;
  94                case ' ':
  95                        arg = prog + len + 1;
  96                        break;
  97                default:
  98                        continue;
  99                }
 100                exit(cmd->exec(cmd->name, arg));
 101        }
 102        die("unrecognized command '%s'", prog);
 103}