git wrapper: basic fixes.

Updates to fix the nits found during the list discussion.

 - Lose PATH_TO_MAN; just rely on execlp() to find whereever the
   "man" command is installed.

 - Do not randomly chdir(), but concatenate to the current
   working directory only if the given path is not absolute.

 - Lose use of glob(); read from exec_path and do sorting
   ourselves -- it is not that much more work.

Signed-off-by: Junio C Hamano <junkio@cox.net>

diff --git a/git.c b/git.c
index 583923d960f4d7e13656f3e6b7b9d8197bfa6a20..b9b8c62f47cc54ef03161e61569dcd0d7b259828 100644 (file)
--- a/git.c
+++ b/git.c
@@ -1,11 +1,13 @@
 #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 <glob.h>
 
 #ifndef PATH_MAX
 # define PATH_MAX 4096
@@ -14,12 +16,6 @@
 static const char git_usage[] =
        "Usage: git [--version] [--exec-path[=GIT_EXEC_PATH]] [--help] COMMAND [ ARGS ]";
 
-struct string_list {
-       size_t len;
-       char *str;
-       struct string_list *next;
-};
-
 /* most gui terms set COLUMNS (although some don't export it) */
 static int term_columns(void)
 {
@@ -32,30 +28,69 @@ static int term_columns(void)
        return 80;
 }
 
+static void oom(void)
+{
+       fprintf(stderr, "git: out of memory\n");
+       exit(1);
+}
+
 static inline void mput_char(char c, unsigned int num)
 {
        while(num--)
                putchar(c);
 }
 
-static void pretty_print_string_list(struct string_list *list, int longest)
+static struct cmdname {
+       size_t len;
+       char name[1];
+} **cmdname;
+static int cmdname_alloc, cmdname_cnt;
+
+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+1);
+       cmdname[cmdname_cnt++] = ent;
+}
+
+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);
+}
+
+static void pretty_print_string_list(struct cmdname **cmdname, int longest)
 {
        int cols = 1;
        int space = longest + 1; /* min 1 SP between words */
        int max_cols = term_columns() - 1; /* don't print *on* the edge */
+       int i;
 
        if (space < max_cols)
                cols = max_cols / space;
 
-       while (list) {
+       qsort(cmdname, cmdname_cnt, sizeof(*cmdname), cmdname_compare);
+
+       for (i = 0; i < cmdname_cnt; ) {
                int c;
                printf("  ");
 
-               for (c = cols; c && list; list = list->next) {
-                       printf("%s", list->str);
+               for (c = cols; c && i < cmdname_cnt; i++) {
+                       printf("%s", cmdname[i]->name);
 
                        if (--c)
-                               mput_char(' ', space - list->len);
+                               mput_char(' ', space - cmdname[i]->len);
                }
                putchar('\n');
        }
@@ -63,54 +98,53 @@ static void pretty_print_string_list(struct string_list *list, int longest)
 
 static void list_commands(const char *exec_path, const char *pattern)
 {
-       struct string_list *list = NULL, *tail = NULL;
-       unsigned int longest = 0, i;
-       glob_t gl;
-
-       if (chdir(exec_path) < 0) {
-               printf("git: '%s': %s\n", exec_path, strerror(errno));
+       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);
        }
 
-       i = glob(pattern, 0, NULL, &gl);
-       switch(i) {
-       case GLOB_NOSPACE:
-               puts("Out of memory when running glob()");
-               exit(2);
-       case GLOB_ABORTED:
-               printf("'%s': Read error: %s\n", exec_path, strerror(errno));
-               exit(2);
-       case GLOB_NOMATCH:
-               printf("No git commands available in '%s'.\n", exec_path);
-               printf("Do you need to specify --exec-path or set GIT_EXEC_PATH?\n");
+       dirlen = strlen(exec_path);
+       if (PATH_MAX - 20 < dirlen) {
+               fprintf(stderr, "git: insanely long exec-path '%s'\n",
+                       exec_path);
                exit(1);
        }
 
-       for (i = 0; i < gl.gl_pathc; i++) {
-               int len = strlen(gl.gl_pathv[i] + 4);
+       memcpy(path, exec_path, dirlen);
+       path[dirlen++] = '/';
+
+       while ((de = readdir(dir)) != NULL) {
+               struct stat st;
+               int entlen;
 
-               if (access(gl.gl_pathv[i], X_OK))
+               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;
 
-               if (longest < len)
-                       longest = len;
+               entlen = strlen(de->d_name);
 
-               if (!tail)
-                       tail = list = malloc(sizeof(struct string_list));
-               else {
-                       tail->next = malloc(sizeof(struct string_list));
-                       tail = tail->next;
-               }
-               tail->len = len;
-               tail->str = gl.gl_pathv[i] + 4;
-               tail->next = NULL;
+               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(list, longest);
+       pretty_print_string_list(cmdname, longest - 4);
        putchar('\n');
 }
 
@@ -146,7 +180,7 @@ static void prepend_to_path(const char *dir, int len)
        int path_len = len;
 
        if (!old_path)
-               old_path = "/bin:/usr/bin:.";
+               old_path = "/usr/local/bin:/usr/bin:/bin";
 
        path_len = len + strlen(old_path) + 1;
 
@@ -160,8 +194,6 @@ static void prepend_to_path(const char *dir, int len)
        setenv("PATH", path, 1);
 }
 
-/* has anyone seen 'man' installed anywhere else than in /usr/bin? */
-#define PATH_TO_MAN "/usr/bin/man"
 static void show_man_page(char *git_cmd)
 {
        char *page;
@@ -177,7 +209,7 @@ static void show_man_page(char *git_cmd)
                page[page_len] = 0;
        }
 
-       execlp(PATH_TO_MAN, "man", page, NULL);
+       execlp("man", "man", page, NULL);
 }
 
 int main(int argc, char **argv, char **envp)
@@ -226,15 +258,25 @@ int main(int argc, char **argv, char **envp)
                show_man_page(argv[i]);
        }
 
-       /* allow relative paths, but run with exact */
-       if (chdir(exec_path)) {
-               printf("git: '%s': %s\n", exec_path, strerror(errno));
-               exit (1);
-       }
-
-       getcwd(git_command, sizeof(git_command));
-       chdir(wd);
+       if (*exec_path != '/') {
+               if (!getcwd(git_command, sizeof(git_command))) {
+                       fprintf(stderr,
+                               "git: cannot determine current directory");
+                       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);
+       }
+       else
+               strcpy(git_command, exec_path);
        len = strlen(git_command);
        prepend_to_path(git_command, len);