exec_cmd.c

   1 #include "cache.h"
   2 #include "exec_cmd.h"
   3 #include "quote.h"
   4 #define MAX_ARGS        32
   5
   6 extern char **environ;
   7 static const char *argv_exec_path;
   8 static const char *argv0_path;
   9
  10 const char *system_path(const char *path)
  11 {
  12         static const char *prefix = PREFIX;
  13         struct strbuf d = STRBUF_INIT;
  14
  15         if (is_absolute_path(path))
  16                 return path;
  17
  18         strbuf_addf(&d, "%s/%s", prefix, path);
  19         path = strbuf_detach(&d, NULL);
  20         return path;
  21 }
  22
  23 const char *git_extract_argv0_path(const char *argv0)
  24 {
  25         const char *slash = argv0 + strlen(argv0);
  26
  27         while (argv0 <= slash && !is_dir_sep(*slash))
  28                 slash--;
  29
  30         if (slash >= argv0) {
  31                 argv0_path = xstrndup(argv0, slash - argv0);
  32                 return slash + 1;
  33         }
  34
  35         return argv0;
  36 }
  37
  38 void git_set_argv_exec_path(const char *exec_path)
  39 {
  40         argv_exec_path = exec_path;
  41 }
  42
  43
  44 /* Returns the highest-priority, location to look for git programs. */
  45 const char *git_exec_path(void)
  46 {
  47         const char *env;
  48
  49         if (argv_exec_path)
  50                 return argv_exec_path;
  51
  52         env = getenv(EXEC_PATH_ENVIRONMENT);
  53         if (env && *env) {
  54                 return env;
  55         }
  56
  57         return system_path(GIT_EXEC_PATH);
  58 }
  59
  60 static void add_path(struct strbuf *out, const char *path)
  61 {
  62         if (path && *path) {
  63                 if (is_absolute_path(path))
  64                         strbuf_addstr(out, path);
  65                 else
  66                         strbuf_addstr(out, make_nonrelative_path(path));
  67
  68                 strbuf_addch(out, PATH_SEP);
  69         }
  70 }
  71
  72 void setup_path(void)
  73 {
  74         const char *old_path = getenv("PATH");
  75         struct strbuf new_path = STRBUF_INIT;
  76
  77         add_path(&new_path, argv_exec_path);
  78         add_path(&new_path, getenv(EXEC_PATH_ENVIRONMENT));
  79         add_path(&new_path, system_path(GIT_EXEC_PATH));
  80         add_path(&new_path, argv0_path);
  81
  82         if (old_path)
  83                 strbuf_addstr(&new_path, old_path);
  84         else
  85                 strbuf_addstr(&new_path, "/usr/local/bin:/usr/bin:/bin");
  86
  87         setenv("PATH", new_path.buf, 1);
  88
  89         strbuf_release(&new_path);
  90 }
  91
  92 const char **prepare_git_cmd(const char **argv)
  93 {
  94         int argc;
  95         const char **nargv;
  96
  97         for (argc = 0; argv[argc]; argc++)
  98                 ; /* just counting */
  99         nargv = xmalloc(sizeof(*nargv) * (argc + 2));
 100
 101         nargv[0] = "git";
 102         for (argc = 0; argv[argc]; argc++)
 103                 nargv[argc + 1] = argv[argc];
 104         nargv[argc + 1] = NULL;
 105         return nargv;
 106 }
 107
 108 int execv_git_cmd(const char **argv) {
 109         const char **nargv = prepare_git_cmd(argv);
 110         trace_argv_printf(nargv, "trace: exec:");
 111
 112         /* execvp() can only ever return if it fails */
 113         execvp("git", (char **)nargv);
 114
 115         trace_printf("trace: exec failed: %s\n", strerror(errno));
 116
 117         free(nargv);
 118         return -1;
 119 }
 120
 121
 122 int execl_git_cmd(const char *cmd,...)
 123 {
 124         int argc;
 125         const char *argv[MAX_ARGS + 1];
 126         const char *arg;
 127         va_list param;
 128
 129         va_start(param, cmd);
 130         argv[0] = cmd;
 131         argc = 1;
 132         while (argc < MAX_ARGS) {
 133                 arg = argv[argc++] = va_arg(param, char *);
 134                 if (!arg)
 135                         break;
 136         }
 137         va_end(param);
 138         if (MAX_ARGS <= argc)
 139                 return error("too many args to run %s", cmd);
 140
 141         argv[argc] = NULL;
 142         return execv_git_cmd(argv);
 143 }