path.con commit Retire support for old environment variables. (a9ab586)
   1/*
   2 * I'm tired of doing "vsnprintf()" etc just to open a
   3 * file, so here's a "return static buffer with printf"
   4 * interface for paths.
   5 *
   6 * It's obviously not thread-safe. Sue me. But it's quite
   7 * useful for doing things like
   8 *
   9 *   f = open(mkpath("%s/%s.git", base, name), O_RDONLY);
  10 *
  11 * which is what it's designed for.
  12 */
  13#include "cache.h"
  14
  15static char pathname[PATH_MAX];
  16static char bad_path[] = "/bad-path/";
  17
  18static char *cleanup_path(char *path)
  19{
  20        /* Clean it up */
  21        if (!memcmp(path, "./", 2)) {
  22                path += 2;
  23                while (*path == '/')
  24                        path++;
  25        }
  26        return path;
  27}
  28
  29char *mkpath(const char *fmt, ...)
  30{
  31        va_list args;
  32        unsigned len;
  33
  34        va_start(args, fmt);
  35        len = vsnprintf(pathname, PATH_MAX, fmt, args);
  36        va_end(args);
  37        if (len >= PATH_MAX)
  38                return bad_path;
  39        return cleanup_path(pathname);
  40}
  41
  42char *git_path(const char *fmt, ...)
  43{
  44        const char *git_dir;
  45        va_list args;
  46        unsigned len;
  47
  48        git_dir = getenv(GIT_DIR_ENVIRONMENT);
  49        if (!git_dir) git_dir = DEFAULT_GIT_DIR_ENVIRONMENT;
  50        len = strlen(git_dir);
  51        if (len > PATH_MAX-100)
  52                return bad_path;
  53        memcpy(pathname, git_dir, len);
  54        if (len && git_dir[len-1] != '/')
  55                pathname[len++] = '/';
  56        va_start(args, fmt);
  57        len += vsnprintf(pathname + len, PATH_MAX - len, fmt, args);
  58        va_end(args);
  59        if (len >= PATH_MAX)
  60                return bad_path;
  61        return cleanup_path(pathname);
  62}
  63
  64
  65/* git_mkstemp() - create tmp file honoring TMPDIR variable */
  66int git_mkstemp(char *path, size_t len, const char *template)
  67{
  68        char *env, *pch = path;
  69
  70        if ((env = getenv("TMPDIR")) == NULL) {
  71                strcpy(pch, "/tmp/");
  72                len -= 5;
  73                pch += 5;
  74        } else {
  75                size_t n = snprintf(pch, len, "%s/", env);
  76
  77                len -= n;
  78                pch += n;
  79        }
  80
  81        safe_strncpy(pch, template, len);
  82
  83        return mkstemp(path);
  84}
  85
  86
  87char *safe_strncpy(char *dest, const char *src, size_t n)
  88{
  89        strncpy(dest, src, n);
  90        dest[n - 1] = '\0';
  91
  92        return dest;
  93}