git log --graph: print '*' for all commits, including merges
[gitweb.git] / git.c
diff --git a/git.c b/git.c
index 0fd95bf751cd5abfeb8a95f3b828adde4537dfde..15a0e71cc1f5d7ad032a2b0591e526f9b0ca8b0b 100644 (file)
--- a/git.c
+++ b/git.c
-#include <stdio.h>
-#include <sys/types.h>
-#include <sys/stat.h>
-#include <dirent.h>
-#include <unistd.h>
-#include <stdlib.h>
-#include <string.h>
-#include <errno.h>
-#include <limits.h>
-#include <stdarg.h>
-#include <sys/ioctl.h>
-#include "git-compat-util.h"
-
-#ifndef PATH_MAX
-# define PATH_MAX 4096
-#endif
+#include "builtin.h"
+#include "exec_cmd.h"
+#include "cache.h"
+#include "quote.h"
 
-static const char git_usage[] =
-       "Usage: git [--version] [--exec-path[=GIT_EXEC_PATH]] [--help] COMMAND [ ARGS ]";
+const char git_usage_string[] =
+       "git [--version] [--exec-path[=GIT_EXEC_PATH]] [-p|--paginate|--no-pager] [--bare] [--git-dir=GIT_DIR] [--work-tree=GIT_WORK_TREE] [--help] COMMAND [ARGS]";
 
-/* most gui terms set COLUMNS (although some don't export it) */
-static int term_columns(void)
-{
-       char *col_string = getenv("COLUMNS");
-       int n_cols = 0;
-
-       if (col_string && (n_cols = atoi(col_string)) > 0)
-               return n_cols;
-
-#ifdef TIOCGWINSZ
-       {
-               struct winsize ws;
-               if (!ioctl(1, TIOCGWINSZ, &ws)) {
-                       if (ws.ws_col)
-                               return ws.ws_col;
-               }
-       }
-#endif
+const char git_more_info_string[] =
+       "See 'git help COMMAND' for more information on a specific command.";
 
-       return 80;
-}
-
-static void oom(void)
+static int handle_options(const char*** argv, int* argc, int* envchanged)
 {
-       fprintf(stderr, "git: out of memory\n");
-       exit(1);
-}
+       int handled = 0;
 
-static inline void mput_char(char c, unsigned int num)
-{
-       while(num--)
-               putchar(c);
-}
+       while (*argc > 0) {
+               const char *cmd = (*argv)[0];
+               if (cmd[0] != '-')
+                       break;
 
-static struct cmdname {
-       size_t len;
-       char name[1];
-} **cmdname;
-static int cmdname_alloc, cmdname_cnt;
+               /*
+                * For legacy reasons, the "version" and "help"
+                * commands can be written with "--" prepended
+                * to make them look like flags.
+                */
+               if (!strcmp(cmd, "--help") || !strcmp(cmd, "--version"))
+                       break;
 
-static void add_cmdname(const char *name, int len)
-{
-       struct cmdname *ent;
-       if (cmdname_alloc <= cmdname_cnt) {
-               cmdname_alloc = cmdname_alloc + 200;
-               cmdname = realloc(cmdname, cmdname_alloc * sizeof(*cmdname));
-               if (!cmdname)
-                       oom();
-       }
-       ent = malloc(sizeof(*ent) + len);
-       if (!ent)
-               oom();
-       ent->len = len;
-       memcpy(ent->name, name, len);
-       ent->name[len] = 0;
-       cmdname[cmdname_cnt++] = ent;
-}
+               /*
+                * Check remaining flags.
+                */
+               if (!prefixcmp(cmd, "--exec-path")) {
+                       cmd += 11;
+                       if (*cmd == '=')
+                               git_set_argv_exec_path(cmd + 1);
+                       else {
+                               puts(git_exec_path());
+                               exit(0);
+                       }
+               } else if (!strcmp(cmd, "-p") || !strcmp(cmd, "--paginate")) {
+                       setup_pager();
+               } else if (!strcmp(cmd, "--no-pager")) {
+                       setenv("GIT_PAGER", "cat", 1);
+                       if (envchanged)
+                               *envchanged = 1;
+               } else if (!strcmp(cmd, "--git-dir")) {
+                       if (*argc < 2) {
+                               fprintf(stderr, "No directory given for --git-dir.\n" );
+                               usage(git_usage_string);
+                       }
+                       setenv(GIT_DIR_ENVIRONMENT, (*argv)[1], 1);
+                       if (envchanged)
+                               *envchanged = 1;
+                       (*argv)++;
+                       (*argc)--;
+                       handled++;
+               } else if (!prefixcmp(cmd, "--git-dir=")) {
+                       setenv(GIT_DIR_ENVIRONMENT, cmd + 10, 1);
+                       if (envchanged)
+                               *envchanged = 1;
+               } else if (!strcmp(cmd, "--work-tree")) {
+                       if (*argc < 2) {
+                               fprintf(stderr, "No directory given for --work-tree.\n" );
+                               usage(git_usage_string);
+                       }
+                       setenv(GIT_WORK_TREE_ENVIRONMENT, (*argv)[1], 1);
+                       if (envchanged)
+                               *envchanged = 1;
+                       (*argv)++;
+                       (*argc)--;
+               } else if (!prefixcmp(cmd, "--work-tree=")) {
+                       setenv(GIT_WORK_TREE_ENVIRONMENT, cmd + 12, 1);
+                       if (envchanged)
+                               *envchanged = 1;
+               } else if (!strcmp(cmd, "--bare")) {
+                       static char git_dir[PATH_MAX+1];
+                       is_bare_repository_cfg = 1;
+                       setenv(GIT_DIR_ENVIRONMENT, getcwd(git_dir, sizeof(git_dir)), 0);
+                       if (envchanged)
+                               *envchanged = 1;
+               } else {
+                       fprintf(stderr, "Unknown option: %s\n", cmd);
+                       usage(git_usage_string);
+               }
 
-static int cmdname_compare(const void *a_, const void *b_)
-{
-       struct cmdname *a = *(struct cmdname **)a_;
-       struct cmdname *b = *(struct cmdname **)b_;
-       return strcmp(a->name, b->name);
+               (*argv)++;
+               (*argc)--;
+               handled++;
+       }
+       return handled;
 }
 
-static void pretty_print_string_list(struct cmdname **cmdname, int longest)
+static int split_cmdline(char *cmdline, const char ***argv)
 {
-       int cols = 1, rows;
-       int space = longest + 1; /* min 1 SP between words */
-       int max_cols = term_columns() - 1; /* don't print *on* the edge */
-       int i, j;
-
-       if (space < max_cols)
-               cols = max_cols / space;
-       rows = (cmdname_cnt + cols - 1) / cols;
-
-       qsort(cmdname, cmdname_cnt, sizeof(*cmdname), cmdname_compare);
-
-       for (i = 0; i < rows; i++) {
-               printf("  ");
-
-               for (j = 0; j < cols; j++) {
-                       int n = j * rows + i;
-                       int size = space;
-                       if (n >= cmdname_cnt)
-                               break;
-                       if (j == cols-1 || n + rows >= cmdname_cnt)
-                               size = 1;
-                       printf("%-*s", size, cmdname[n]->name);
+       int src, dst, count = 0, size = 16;
+       char quoted = 0;
+
+       *argv = xmalloc(sizeof(char*) * size);
+
+       /* split alias_string */
+       (*argv)[count++] = cmdline;
+       for (src = dst = 0; cmdline[src];) {
+               char c = cmdline[src];
+               if (!quoted && isspace(c)) {
+                       cmdline[dst++] = 0;
+                       while (cmdline[++src]
+                                       && isspace(cmdline[src]))
+                               ; /* skip */
+                       if (count >= size) {
+                               size += 16;
+                               *argv = xrealloc(*argv, sizeof(char*) * size);
+                       }
+                       (*argv)[count++] = cmdline + dst;
+               } else if(!quoted && (c == '\'' || c == '"')) {
+                       quoted = c;
+                       src++;
+               } else if (c == quoted) {
+                       quoted = 0;
+                       src++;
+               } else {
+                       if (c == '\\' && quoted != '\'') {
+                               src++;
+                               c = cmdline[src];
+                               if (!c) {
+                                       free(*argv);
+                                       *argv = NULL;
+                                       return error("cmdline ends with \\");
+                               }
+                       }
+                       cmdline[dst++] = c;
+                       src++;
                }
-               putchar('\n');
        }
-}
 
-static void list_commands(const char *exec_path, const char *pattern)
-{
-       unsigned int longest = 0;
-       char path[PATH_MAX];
-       int dirlen;
-       DIR *dir = opendir(exec_path);
-       struct dirent *de;
-
-       if (!dir) {
-               fprintf(stderr, "git: '%s': %s\n", exec_path, strerror(errno));
-               exit(1);
-       }
+       cmdline[dst] = 0;
 
-       dirlen = strlen(exec_path);
-       if (PATH_MAX - 20 < dirlen) {
-               fprintf(stderr, "git: insanely long exec-path '%s'\n",
-                       exec_path);
-               exit(1);
+       if (quoted) {
+               free(*argv);
+               *argv = NULL;
+               return error("unclosed quote");
        }
 
-       memcpy(path, exec_path, dirlen);
-       path[dirlen++] = '/';
-
-       while ((de = readdir(dir)) != NULL) {
-               struct stat st;
-               int entlen;
-
-               if (strncmp(de->d_name, "git-", 4))
-                       continue;
-               strcpy(path+dirlen, de->d_name);
-               if (stat(path, &st) || /* stat, not lstat */
-                   !S_ISREG(st.st_mode) ||
-                   !(st.st_mode & S_IXUSR))
-                       continue;
-
-               entlen = strlen(de->d_name);
-               if (4 < entlen && !strcmp(de->d_name + entlen - 4, ".exe"))
-                       entlen -= 4;
-
-               if (longest < entlen)
-                       longest = entlen;
-
-               add_cmdname(de->d_name + 4, entlen-4);
-       }
-       closedir(dir);
-
-       printf("git commands available in '%s'\n", exec_path);
-       printf("----------------------------");
-       mput_char('-', strlen(exec_path));
-       putchar('\n');
-       pretty_print_string_list(cmdname, longest - 4);
-       putchar('\n');
+       return count;
 }
 
-#ifdef __GNUC__
-static void cmd_usage(const char *exec_path, const char *fmt, ...)
-       __attribute__((__format__(__printf__, 2, 3), __noreturn__));
-#endif
-static void cmd_usage(const char *exec_path, const char *fmt, ...)
+static int handle_alias(int *argcp, const char ***argv)
 {
-       if (fmt) {
-               va_list ap;
-
-               va_start(ap, fmt);
-               printf("git: ");
-               vprintf(fmt, ap);
-               va_end(ap);
-               putchar('\n');
+       int envchanged = 0, ret = 0, saved_errno = errno;
+       const char *subdir;
+       int count, option_count;
+       const char** new_argv;
+       const char *alias_command;
+       char *alias_string;
+       int unused_nongit;
+
+       subdir = setup_git_directory_gently(&unused_nongit);
+
+       alias_command = (*argv)[0];
+       alias_string = alias_lookup(alias_command);
+       if (alias_string) {
+               if (alias_string[0] == '!') {
+                       if (*argcp > 1) {
+                               struct strbuf buf;
+
+                               strbuf_init(&buf, PATH_MAX);
+                               strbuf_addstr(&buf, alias_string);
+                               sq_quote_argv(&buf, (*argv) + 1, PATH_MAX);
+                               free(alias_string);
+                               alias_string = buf.buf;
+                       }
+                       trace_printf("trace: alias to shell cmd: %s => %s\n",
+                                    alias_command, alias_string + 1);
+                       ret = system(alias_string + 1);
+                       if (ret >= 0 && WIFEXITED(ret) &&
+                           WEXITSTATUS(ret) != 127)
+                               exit(WEXITSTATUS(ret));
+                       die("Failed to run '%s' when expanding alias '%s'\n",
+                           alias_string + 1, alias_command);
+               }
+               count = split_cmdline(alias_string, &new_argv);
+               option_count = handle_options(&new_argv, &count, &envchanged);
+               if (envchanged)
+                       die("alias '%s' changes environment variables\n"
+                                "You can use '!git' in the alias to do this.",
+                                alias_command);
+               memmove(new_argv - option_count, new_argv,
+                               count * sizeof(char *));
+               new_argv -= option_count;
+
+               if (count < 1)
+                       die("empty alias for %s", alias_command);
+
+               if (!strcmp(alias_command, new_argv[0]))
+                       die("recursive alias: %s", alias_command);
+
+               trace_argv_printf(new_argv,
+                                 "trace: alias expansion: %s =>",
+                                 alias_command);
+
+               new_argv = xrealloc(new_argv, sizeof(char*) *
+                                   (count + *argcp + 1));
+               /* insert after command name */
+               memcpy(new_argv + count, *argv + 1, sizeof(char*) * *argcp);
+               new_argv[count+*argcp] = NULL;
+
+               *argv = new_argv;
+               *argcp += count - 1;
+
+               ret = 1;
        }
-       else
-               puts(git_usage);
 
-       putchar('\n');
+       if (subdir)
+               chdir(subdir);
 
-       if(exec_path)
-               list_commands(exec_path, "git-*");
+       errno = saved_errno;
 
-       exit(1);
+       return ret;
 }
 
-static void prepend_to_path(const char *dir, int len)
-{
-       char *path, *old_path = getenv("PATH");
-       int path_len = len;
-
-       if (!old_path)
-               old_path = "/usr/local/bin:/usr/bin:/bin";
+const char git_version_string[] = GIT_VERSION;
 
-       path_len = len + strlen(old_path) + 1;
+#define RUN_SETUP      (1<<0)
+#define USE_PAGER      (1<<1)
+/*
+ * require working tree to be present -- anything uses this needs
+ * RUN_SETUP for reading from the configuration file.
+ */
+#define NEED_WORK_TREE (1<<2)
 
-       path = malloc(path_len + 1);
+struct cmd_struct {
+       const char *cmd;
+       int (*fn)(int, const char **, const char *);
+       int option;
+};
 
-       memcpy(path, dir, len);
-       path[len] = ':';
-       memcpy(path + len + 1, old_path, path_len - len);
-
-       setenv("PATH", path, 1);
+static int run_command(struct cmd_struct *p, int argc, const char **argv)
+{
+       int status;
+       struct stat st;
+       const char *prefix;
+
+       prefix = NULL;
+       if (p->option & RUN_SETUP)
+               prefix = setup_git_directory();
+       if (p->option & USE_PAGER)
+               setup_pager();
+       if (p->option & NEED_WORK_TREE)
+               setup_work_tree();
+
+       trace_argv_printf(argv, "trace: built-in: git");
+
+       status = p->fn(argc, argv, prefix);
+       if (status)
+               return status & 0xff;
+
+       /* Somebody closed stdout? */
+       if (fstat(fileno(stdout), &st))
+               return 0;
+       /* Ignore write errors for pipes and sockets.. */
+       if (S_ISFIFO(st.st_mode) || S_ISSOCK(st.st_mode))
+               return 0;
+
+       /* Check for ENOSPC and EIO errors.. */
+       if (fflush(stdout))
+               die("write failure on standard output: %s", strerror(errno));
+       if (ferror(stdout))
+               die("unknown write failure on standard output");
+       if (fclose(stdout))
+               die("close failed on standard output: %s", strerror(errno));
+       return 0;
 }
 
-static void show_man_page(char *git_cmd)
+static void handle_internal_command(int argc, const char **argv)
 {
-       char *page;
-
-       if (!strncmp(git_cmd, "git", 3))
-               page = git_cmd;
-       else {
-               int page_len = strlen(git_cmd) + 4;
-
-               page = malloc(page_len + 1);
-               strcpy(page, "git-");
-               strcpy(page + 4, git_cmd);
-               page[page_len] = 0;
+       const char *cmd = argv[0];
+       static struct cmd_struct commands[] = {
+               { "add", cmd_add, RUN_SETUP | NEED_WORK_TREE },
+               { "annotate", cmd_annotate, RUN_SETUP },
+               { "apply", cmd_apply },
+               { "archive", cmd_archive },
+               { "blame", cmd_blame, RUN_SETUP },
+               { "branch", cmd_branch, RUN_SETUP },
+               { "bundle", cmd_bundle },
+               { "cat-file", cmd_cat_file, RUN_SETUP },
+               { "checkout", cmd_checkout, RUN_SETUP | NEED_WORK_TREE },
+               { "checkout-index", cmd_checkout_index,
+                       RUN_SETUP | NEED_WORK_TREE},
+               { "check-ref-format", cmd_check_ref_format },
+               { "check-attr", cmd_check_attr, RUN_SETUP | NEED_WORK_TREE },
+               { "cherry", cmd_cherry, RUN_SETUP },
+               { "cherry-pick", cmd_cherry_pick, RUN_SETUP | NEED_WORK_TREE },
+               { "clone", cmd_clone },
+               { "clean", cmd_clean, RUN_SETUP | NEED_WORK_TREE },
+               { "commit", cmd_commit, RUN_SETUP | NEED_WORK_TREE },
+               { "commit-tree", cmd_commit_tree, RUN_SETUP },
+               { "config", cmd_config },
+               { "count-objects", cmd_count_objects, RUN_SETUP },
+               { "describe", cmd_describe, RUN_SETUP },
+               { "diff", cmd_diff },
+               { "diff-files", cmd_diff_files, RUN_SETUP },
+               { "diff-index", cmd_diff_index, RUN_SETUP },
+               { "diff-tree", cmd_diff_tree, RUN_SETUP },
+               { "fast-export", cmd_fast_export, RUN_SETUP },
+               { "fetch", cmd_fetch, RUN_SETUP },
+               { "fetch-pack", cmd_fetch_pack, RUN_SETUP },
+               { "fetch--tool", cmd_fetch__tool, RUN_SETUP },
+               { "fmt-merge-msg", cmd_fmt_merge_msg, RUN_SETUP },
+               { "for-each-ref", cmd_for_each_ref, RUN_SETUP },
+               { "format-patch", cmd_format_patch, RUN_SETUP },
+               { "fsck", cmd_fsck, RUN_SETUP },
+               { "fsck-objects", cmd_fsck, RUN_SETUP },
+               { "gc", cmd_gc, RUN_SETUP },
+               { "get-tar-commit-id", cmd_get_tar_commit_id },
+               { "grep", cmd_grep, RUN_SETUP | USE_PAGER },
+               { "help", cmd_help },
+#ifndef NO_CURL
+               { "http-fetch", cmd_http_fetch, RUN_SETUP },
+#endif
+               { "init", cmd_init_db },
+               { "init-db", cmd_init_db },
+               { "log", cmd_log, RUN_SETUP | USE_PAGER },
+               { "ls-files", cmd_ls_files, RUN_SETUP },
+               { "ls-tree", cmd_ls_tree, RUN_SETUP },
+               { "ls-remote", cmd_ls_remote },
+               { "mailinfo", cmd_mailinfo },
+               { "mailsplit", cmd_mailsplit },
+               { "merge-base", cmd_merge_base, RUN_SETUP },
+               { "merge-file", cmd_merge_file },
+               { "merge-ours", cmd_merge_ours, RUN_SETUP },
+               { "merge-recursive", cmd_merge_recursive, RUN_SETUP | NEED_WORK_TREE },
+               { "merge-subtree", cmd_merge_recursive, RUN_SETUP | NEED_WORK_TREE },
+               { "mv", cmd_mv, RUN_SETUP | NEED_WORK_TREE },
+               { "name-rev", cmd_name_rev, RUN_SETUP },
+               { "pack-objects", cmd_pack_objects, RUN_SETUP },
+               { "peek-remote", cmd_ls_remote },
+               { "pickaxe", cmd_blame, RUN_SETUP },
+               { "prune", cmd_prune, RUN_SETUP },
+               { "prune-packed", cmd_prune_packed, RUN_SETUP },
+               { "push", cmd_push, RUN_SETUP },
+               { "read-tree", cmd_read_tree, RUN_SETUP },
+               { "reflog", cmd_reflog, RUN_SETUP },
+               { "remote", cmd_remote, RUN_SETUP },
+               { "repo-config", cmd_config },
+               { "rerere", cmd_rerere, RUN_SETUP },
+               { "reset", cmd_reset, RUN_SETUP },
+               { "rev-list", cmd_rev_list, RUN_SETUP },
+               { "rev-parse", cmd_rev_parse },
+               { "revert", cmd_revert, RUN_SETUP | NEED_WORK_TREE },
+               { "rm", cmd_rm, RUN_SETUP },
+               { "send-pack", cmd_send_pack, RUN_SETUP },
+               { "shortlog", cmd_shortlog, USE_PAGER },
+               { "show-branch", cmd_show_branch, RUN_SETUP },
+               { "show", cmd_show, RUN_SETUP | USE_PAGER },
+               { "status", cmd_status, RUN_SETUP | NEED_WORK_TREE | USE_PAGER },
+               { "stripspace", cmd_stripspace },
+               { "symbolic-ref", cmd_symbolic_ref, RUN_SETUP },
+               { "tag", cmd_tag, RUN_SETUP },
+               { "tar-tree", cmd_tar_tree },
+               { "unpack-objects", cmd_unpack_objects, RUN_SETUP },
+               { "update-index", cmd_update_index, RUN_SETUP },
+               { "update-ref", cmd_update_ref, RUN_SETUP },
+               { "upload-archive", cmd_upload_archive },
+               { "verify-tag", cmd_verify_tag, RUN_SETUP },
+               { "version", cmd_version },
+               { "whatchanged", cmd_whatchanged, RUN_SETUP | USE_PAGER },
+               { "write-tree", cmd_write_tree, RUN_SETUP },
+               { "verify-pack", cmd_verify_pack },
+               { "show-ref", cmd_show_ref, RUN_SETUP },
+               { "pack-refs", cmd_pack_refs, RUN_SETUP },
+       };
+       int i;
+
+       /* Turn "git cmd --help" into "git help cmd" */
+       if (argc > 1 && !strcmp(argv[1], "--help")) {
+               argv[1] = argv[0];
+               argv[0] = cmd = "help";
        }
 
-       execlp("man", "man", page, NULL);
+       for (i = 0; i < ARRAY_SIZE(commands); i++) {
+               struct cmd_struct *p = commands+i;
+               if (strcmp(p->cmd, cmd))
+                       continue;
+               exit(run_command(p, argc, argv));
+       }
 }
 
-int main(int argc, char **argv, char **envp)
+int main(int argc, const char **argv)
 {
-       char git_command[PATH_MAX + 1];
-       char wd[PATH_MAX + 1];
-       int i, len, show_help = 0;
-       char *exec_path = getenv("GIT_EXEC_PATH");
-
-       getcwd(wd, PATH_MAX);
-
-       if (!exec_path)
-               exec_path = GIT_EXEC_PATH;
-
-       for (i = 1; i < argc; i++) {
-               char *arg = argv[i];
-
-               if (strncmp(arg, "--", 2))
-                       break;
-
-               arg += 2;
-
-               if (!strncmp(arg, "exec-path", 9)) {
-                       arg += 9;
-                       if (*arg == '=')
-                               exec_path = arg + 1;
-                       else {
-                               puts(exec_path);
-                               exit(0);
-                       }
-               }
-               else if (!strcmp(arg, "version")) {
-                       printf("git version %s\n", GIT_VERSION);
-                       exit(0);
-               }
-               else if (!strcmp(arg, "help"))
-                       show_help = 1;
-               else if (!show_help)
-                       cmd_usage(NULL, NULL);
+       const char *cmd = argv[0] ? argv[0] : "git-help";
+       char *slash = strrchr(cmd, '/');
+       const char *cmd_path = NULL;
+       int done_alias = 0;
+
+       /*
+        * Take the basename of argv[0] as the command
+        * name, and the dirname as the default exec_path
+        * if we don't have anything better.
+        */
+       if (slash) {
+               *slash++ = 0;
+               cmd_path = cmd;
+               cmd = slash;
        }
 
-       if (i >= argc || show_help) {
-               if (i >= argc)
-                       cmd_usage(exec_path, NULL);
+       /*
+        * "git-xxxx" is the same as "git xxxx", but we obviously:
+        *
+        *  - cannot take flags in between the "git" and the "xxxx".
+        *  - cannot execute it externally (since it would just do
+        *    the same thing over again)
+        *
+        * So we just directly call the internal command handler, and
+        * die if that one cannot handle it.
+        */
+       if (!prefixcmp(cmd, "git-")) {
+               cmd += 4;
+               argv[0] = cmd;
+               handle_internal_command(argc, argv);
+               die("cannot handle %s internally", cmd);
+       }
 
-               show_man_page(argv[i]);
+       /* Look for flags.. */
+       argv++;
+       argc--;
+       handle_options(&argv, &argc, NULL);
+       if (argc > 0) {
+               if (!prefixcmp(argv[0], "--"))
+                       argv[0] += 2;
+       } else {
+               /* The user didn't specify a command; give them help */
+               printf("usage: %s\n\n", git_usage_string);
+               list_common_cmds_help();
+               printf("\n%s\n", git_more_info_string);
+               exit(1);
+       }
+       cmd = argv[0];
+
+       /*
+        * We use PATH to find git commands, but we prepend some higher
+        * precidence paths: the "--exec-path" option, the GIT_EXEC_PATH
+        * environment, and the $(gitexecdir) from the Makefile at build
+        * time.
+        */
+       setup_path(cmd_path);
+
+       while (1) {
+               /* See if it's an internal command */
+               handle_internal_command(argc, argv);
+
+               /* .. then try the external ones */
+               execv_git_cmd(argv);
+
+               /* It could be an alias -- this works around the insanity
+                * of overriding "git log" with "git show" by having
+                * alias.log = show
+                */
+               if (done_alias || !handle_alias(&argc, &argv))
+                       break;
+               done_alias = 1;
        }
 
-       if (*exec_path != '/') {
-               if (!getcwd(git_command, sizeof(git_command))) {
-                       fprintf(stderr,
-                               "git: cannot determine current directory");
+       if (errno == ENOENT) {
+               if (done_alias) {
+                       fprintf(stderr, "Expansion of alias '%s' failed; "
+                               "'%s' is not a git-command\n",
+                               cmd, argv[0]);
                        exit(1);
                }
-               len = strlen(git_command);
-
-               /* Trivial cleanup */
-               while (!strncmp(exec_path, "./", 2)) {
-                       exec_path += 2;
-                       while (*exec_path == '/')
-                               exec_path++;
-               }
-               snprintf(git_command + len, sizeof(git_command) - len,
-                        "/%s", exec_path);
+               help_unknown_cmd(cmd);
        }
-       else
-               strcpy(git_command, exec_path);
-       len = strlen(git_command);
-       prepend_to_path(git_command, len);
-
-       len += snprintf(git_command + len, sizeof(git_command) - len,
-                       "/git-%s", argv[i]);
-       if (sizeof(git_command) <= len) {
-               fprintf(stderr, "git: command name given is too long.\n");
-               exit(1);
-       }
-
-       /* execve() can only ever return if it fails */
-       execve(git_command, &argv[i], envp);
-
-       if (errno == ENOENT)
-               cmd_usage(exec_path, "'%s' is not a git-command", argv[i]);
 
        fprintf(stderr, "Failed to run command '%s': %s\n",
-               git_command, strerror(errno));
+               cmd, strerror(errno));
 
        return 1;
 }