+char *replace_env(const char *format, char **env) {
+ enum {
+ WORD,
+ DOLLAR,
+ VARIABLE
+ } state = WORD;
+
+ const char *e, *word = format;
+ char *r = NULL, *k;
+
+ assert(format);
+
+ for (e = format; *e; e ++) {
+
+ switch (state) {
+
+ case WORD:
+ if (*e == '$')
+ state = DOLLAR;
+ break;
+
+ case DOLLAR:
+ if (*e == '(') {
+ if (!(k = strnappend(r, word, e-word-1)))
+ goto fail;
+
+ free(r);
+ r = k;
+
+ word = e-1;
+ state = VARIABLE;
+
+ } else if (*e == '$') {
+ if (!(k = strnappend(r, word, e-word)))
+ goto fail;
+
+ free(r);
+ r = k;
+
+ word = e+1;
+ state = WORD;
+ } else
+ state = WORD;
+ break;
+
+ case VARIABLE:
+ if (*e == ')') {
+ char *t;
+
+ if ((t = strv_env_get_with_length(env, word+2, e-word-2))) {
+ if (!(k = strappend(r, t)))
+ goto fail;
+
+ free(r);
+ r = k;
+
+ word = e+1;
+ }
+
+ state = WORD;
+ }
+ break;
+ }
+ }
+
+ if (!(k = strnappend(r, word, e-word)))
+ goto fail;
+
+ free(r);
+ return k;
+
+fail:
+ free(r);
+ return NULL;
+}
+
+char **replace_env_argv(char **argv, char **env) {
+ char **r, **i;
+ unsigned k = 0;
+
+ if (!(r = new(char*, strv_length(argv)+1)))
+ return NULL;
+
+ STRV_FOREACH(i, argv) {
+ if (!(r[k++] = replace_env(*i, env))) {
+ strv_free(r);
+ return NULL;
+ }
+ }
+
+ r[k] = NULL;
+ return r;
+}
+
+int columns(void) {
+ static __thread int parsed_columns = 0;
+ const char *e;
+
+ if (parsed_columns > 0)
+ return parsed_columns;
+
+ if ((e = getenv("COLUMNS")))
+ parsed_columns = atoi(e);
+
+ if (parsed_columns <= 0) {
+ struct winsize ws;
+ zero(ws);
+
+ if (ioctl(STDIN_FILENO, TIOCGWINSZ, &ws) >= 0)
+ parsed_columns = ws.ws_col;
+ }
+
+ if (parsed_columns <= 0)
+ parsed_columns = 80;
+
+ return parsed_columns;
+}
+
+int running_in_chroot(void) {
+ struct stat a, b;
+
+ zero(a);
+ zero(b);
+
+ /* Only works as root */
+
+ if (stat("/proc/1/root", &a) < 0)
+ return -errno;
+
+ if (stat("/", &b) < 0)
+ return -errno;
+
+ return
+ a.st_dev != b.st_dev ||
+ a.st_ino != b.st_ino;
+}
+