On Mon, Aug 28, 2017 at 09:38:13PM +0100, Sami Kerola wrote:
> Less code, less bugs. And if there are bugs at least share them with all
> other programs that use getusershell(3) from libc.
Is it portable? ulibC etc.. ?
>
> Signed-off-by: Sami Kerola <kerolasa@xxxxxx>
> ---
> login-utils/chsh.c | 98 ++++++++++--------------------------------------------
> 1 file changed, 18 insertions(+), 80 deletions(-)
>
> diff --git a/login-utils/chsh.c b/login-utils/chsh.c
> index 4721c870e..c267c7272 100644
> --- a/login-utils/chsh.c
> +++ b/login-utils/chsh.c
> @@ -67,9 +67,6 @@ struct sinfo {
> char *shell;
> };
>
> -/* global due readline completion */
> -static char **global_shells;
> -
> static void __attribute__((__noreturn__)) usage(void)
> {
> FILE *fp = stdout;
> @@ -89,79 +86,26 @@ static void __attribute__((__noreturn__)) usage(void)
> exit(EXIT_SUCCESS);
> }
>
> -/*
> - * free_shells () -- free shells allocations.
> - */
> -static void free_shells(void)
> -{
> - if (global_shells) {
> - char **s;
> -
> - for (s = global_shells; *s; s++)
> - free(*s);
> - free(global_shells);
> - }
> -}
> -
> -/*
> - * init_shells () -- reads /etc/shells into global_shells
> - */
> -static int init_shells(void)
> -{
> - FILE *fp;
> - char *buf = NULL;
> - size_t sz = 0, shellsz = 8, n = 0;
> - ssize_t len;
> -
> - if (global_shells)
> - return 0; /* already initialized */
> -
> - fp = fopen(_PATH_SHELLS, "r");
> - if (!fp)
> - return 1;
> -
> - global_shells = xmalloc(sizeof(char *) * shellsz);
> -
> - while ((len = getline(&buf, &sz, fp)) != -1) {
> - /* ignore comments and blank lines */
> - if (*buf == '#' || len < 2)
> - continue;
> - /* strip the ending newline */
> - if (buf[len - 1] == '\n')
> - buf[len - 1] = 0;
> - global_shells[n++] = buf;
> - if (shellsz < n) {
> - shellsz *= 2;
> - global_shells = xrealloc(global_shells, sizeof(char *) * shellsz);
> - }
> - buf = NULL;
> - }
> -
> - free(buf);
> - global_shells[n] = NULL;
> -
> - fclose(fp);
> - atexit(free_shells);
> -
> - return 0;
> -}
> -
> /*
> * is_known_shell() -- if the given shell appears in /etc/shells,
> * return true. if not, return false.
> */
> static int is_known_shell(const char *shell_name)
> {
> - char **s;
> + char *s, ret = 0;
>
> - if (!global_shells || !shell_name)
> + if (!shell_name)
> return 0;
>
> - for (s = global_shells; *s; s++) {
> - if (strcmp(shell_name, *s) == 0)
> - return 1;
> + setusershell();
> + while ((s = getusershell())) {
> + if (strcmp(shell_name, s) == 0) {
> + ret = 1;
> + break;
> + }
> }
> - return 0;
> + endusershell();
> + return ret;
> }
>
> /*
> @@ -169,29 +113,25 @@ static int is_known_shell(const char *shell_name)
> */
> static void print_shells(void)
> {
> - char **s;
> -
> - if (!global_shells)
> - return;
> + char *s;
>
> - for (s = global_shells; *s; s++)
> - printf("%s\n", *s);
> + while ((s = getusershell()))
> + printf("%s\n", s);
> + endusershell();
> }
>
> #ifdef HAVE_LIBREADLINE
> static char *shell_name_generator(const char *text, int state)
> {
> - static size_t len, idx;
> + static size_t len;
> char *s;
>
> - if (!global_shells)
> - return NULL;
> -
> if (!state) {
> - idx = 0;
> + setusershell();
> len = strlen(text);
> }
> - while ((s = global_shells[idx++])) {
> +
> + while ((s = getusershell())) {
> if (strncmp(s, text, len) == 0)
> return xstrdup(s);
> }
> @@ -232,7 +172,6 @@ static void parse_argv(int argc, char **argv, struct sinfo *pinfo)
> case 'h':
> usage();
> case 'l':
> - init_shells();
> print_shells();
> exit(EXIT_SUCCESS);
> case 's':
> @@ -386,7 +325,6 @@ int main(int argc, char **argv)
> _("running UID doesn't match UID of user we're "
> "altering, shell change denied"));
> }
> - init_shells();
> if (uid != 0 && !is_known_shell(oldshell)) {
> errno = EACCES;
> err(EXIT_FAILURE, _("your shell is not in %s, "
> --
> 2.14.1
>
> --
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>
--
Karel Zak <kzak@xxxxxxxxxx>
http://karelzak.blogspot.com
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