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;
  26
  27         if (!argv0 || !*argv0)
  28                 return NULL;
  29         slash = argv0 + strlen(argv0);
  30
  31         while (argv0 <= slash && !is_dir_sep(*slash))
  32                 slash--;
  33
  34         if (slash >= argv0) {
  35                 argv0_path = xstrndup(argv0, slash - argv0);
  36                 return slash + 1;
  37         }
  38
  39         return argv0;
  40 }
  41
  42 void git_set_argv_exec_path(const char *exec_path)
  43 {
  44         argv_exec_path = exec_path;
  45 }
  46
  47
  48 /* Returns the highest-priority, location to look for git programs. */
  49 const char *git_exec_path(void)
  50 {
  51         const char *env;
  52
  53         if (argv_exec_path)
  54                 return argv_exec_path;
  55
  56         env = getenv(EXEC_PATH_ENVIRONMENT);
  57         if (env && *env) {
  58                 return env;
  59         }
  60
  61         return system_path(GIT_EXEC_PATH);
  62 }
  63
  64 static void add_path(struct strbuf *out, const char *path)
  65 {
  66         if (path && *path) {
  67                 if (is_absolute_path(path))
  68                         strbuf_addstr(out, path);
  69                 else
  70                         strbuf_addstr(out, make_nonrelative_path(path));
  71
  72                 strbuf_addch(out, PATH_SEP);
  73         }
  74 }
  75
  76 void setup_path(void)
  77 {
  78         const char *old_path = getenv("PATH");
  79         struct strbuf new_path = STRBUF_INIT;
  80
  81         add_path(&new_path, argv_exec_path);
  82         add_path(&new_path, getenv(EXEC_PATH_ENVIRONMENT));
  83         add_path(&new_path, system_path(GIT_EXEC_PATH));
  84         add_path(&new_path, argv0_path);
  85
  86         if (old_path)
  87                 strbuf_addstr(&new_path, old_path);
  88         else
  89                 strbuf_addstr(&new_path, "/usr/local/bin:/usr/bin:/bin");
  90
  91         setenv("PATH", new_path.buf, 1);
  92
  93         strbuf_release(&new_path);
  94 }
  95
  96 const char **prepare_git_cmd(const char **argv)
  97 {
  98         int argc;
  99         const char **nargv;
 100
 101         for (argc = 0; argv[argc]; argc++)
 102                 ; /* just counting */
 103         nargv = xmalloc(sizeof(*nargv) * (argc + 2));
 104
 105         nargv[0] = "git";
 106         for (argc = 0; argv[argc]; argc++)
 107                 nargv[argc + 1] = argv[argc];
 108         nargv[argc + 1] = NULL;
 109         return nargv;
 110 }
 111
 112 int execv_git_cmd(const char **argv) {
 113         const char **nargv = prepare_git_cmd(argv);
 114         trace_argv_printf(nargv, "trace: exec:");
 115
 116         /* execvp() can only ever return if it fails */
 117         execvp("git", (char **)nargv);
 118
 119         trace_printf("trace: exec failed: %s\n", strerror(errno));
 120
 121         free(nargv);
 122         return -1;
 123 }
 124
 125
 126 int execl_git_cmd(const char *cmd,...)
 127 {
 128         int argc;
 129         const char *argv[MAX_ARGS + 1];
 130         const char *arg;
 131         va_list param;
 132
 133         va_start(param, cmd);
 134         argv[0] = cmd;
 135         argc = 1;
 136         while (argc < MAX_ARGS) {
 137                 arg = argv[argc++] = va_arg(param, char *);
 138                 if (!arg)
 139                         break;
 140         }
 141         va_end(param);
 142         if (MAX_ARGS <= argc)
 143                 return error("too many args to run %s", cmd);
 144
 145         argv[argc] = NULL;
 146         return execv_git_cmd(argv);
 147 }