chsh: set few variables read-only and rename one of them

This change also improves couple variable initializations.

Signed-off-by: Sami Kerola <kerolasa@iki.fi>

diff --git a/login-utils/chsh.c b/login-utils/chsh.c
index 9ed4d06e5e6277eb8cc5b45e25237338ebcbae83..a31641565fd42a64e1f2648d666b1ae9e958b511 100644 (file)
--- a/login-utils/chsh.c
+++ b/login-utils/chsh.c
@@ -83,7 +83,7 @@ static void __attribute__((__noreturn__)) usage (FILE *fp)
  *     return true.  if not, return false.
  *     if the given shell is NULL, /etc/shells is outputted to stdout.
  */
-static int get_shell_list(char *shell_name)
+static int get_shell_list(const char *shell_name)
 {
        FILE *fp;
        int found;
@@ -206,7 +206,7 @@ static char *prompt(char *question, char *def_val)
  *     an error and return (-1).
  *     if the shell is a bad idea, print a warning.
  */
-static int check_shell(char *shell)
+static int check_shell(const char *shell)
 {
        if (!shell)
                return -1;
@@ -251,9 +251,9 @@ static int check_shell(char *shell)
 
 int main(int argc, char **argv)
 {
-       char *shell, *oldshell;
-       uid_t uid;
-       struct sinfo info;
+       char *oldshell;
+       const uid_t uid = getuid();
+       struct sinfo info = { 0 };
        struct passwd *pw;
 
        sanitize_env();
@@ -262,11 +262,7 @@ int main(int argc, char **argv)
        textdomain(PACKAGE);
        atexit(close_stdout);
 
-       uid = getuid();
-       memset(&info, 0, sizeof(info));
-
        parse_argv(argc, argv, &info);
-       pw = NULL;
        if (!info.username) {
                pw = getpwuid(uid);
                if (!pw)
@@ -327,33 +323,31 @@ int main(int argc, char **argv)
                                    "shell change denied"), _PATH_SHELLS);
        }
 
-       shell = info.shell;
-
        printf(_("Changing shell for %s.\n"), pw->pw_name);
 
 #if !defined(HAVE_LIBUSER) && defined(CHFN_CHSH_PASSWORD)
-       if(!auth_pam("chsh", uid, pw->pw_name)) {
+       if (!auth_pam("chsh", uid, pw->pw_name)) {
                return EXIT_FAILURE;
        }
 #endif
-       if (!shell) {
-               shell = prompt(_("New shell"), oldshell);
-               if (!shell)
+       if (!info.shell) {
+               info.shell = prompt(_("New shell"), oldshell);
+               if (!info.shell)
                        return EXIT_SUCCESS;
        }
 
-       if (check_shell(shell) < 0)
+       if (check_shell(info.shell) < 0)
                return EXIT_FAILURE;
 
-       if (strcmp(oldshell, shell) == 0)
+       if (strcmp(oldshell, info.shell) == 0)
                errx(EXIT_SUCCESS, _("Shell not changed."));
 
 #ifdef HAVE_LIBUSER
        if (set_value_libuser("chsh", pw->pw_name, uid,
-           LU_LOGINSHELL, shell) < 0)
+           LU_LOGINSHELL, info.shell) < 0)
                errx(EXIT_FAILURE, _("Shell *NOT* changed.  Try again later."));
 #else
-       pw->pw_shell = shell;
+       pw->pw_shell = info.shell;
        if (setpwnam(pw) < 0)
                err(EXIT_FAILURE, _("setpwnam failed\n"
                        "Shell *NOT* changed.  Try again later."));