[hackers] [ubase] Inform the user if exec*() fails || sin

[git]

commit da215823a36a86eaaa593098c0244e5d9e5e08bb
Author: sin <s...@2f30.org>
Date:   Tue Jun 3 12:29:16 2014 +0100

    Inform the user if exec*() fails

diff --git a/su.c b/su.c
index 2f7eace..8b2d154 100644
--- a/su.c
+++ b/su.c
@@ -16,7 +16,7 @@
 extern char **environ;
 
 static const char *randreply(void);
-static void dologin(struct passwd *);
+static int dologin(struct passwd *);
 
 static void
 usage(void)
@@ -119,7 +119,7 @@ dosu:
                eprintf("setuid:");
 
        if (lflag) {
-               dologin(pw);
+               return dologin(pw);
        } else {
                newargv = (char *const[]){pw->pw_shell, NULL};
                if (!pflag) {
@@ -136,8 +136,10 @@ dosu:
                        setenv("PATH", ENV_PATH, 1);
                execve(pflag ? getenv("SHELL") : pw->pw_shell,
                       newargv, environ);
+               weprintf("execve %s:", pw->pw_shell);
+               return (errno == ENOENT) ? 127 : 126;
        }
-       return (errno == ENOENT) ? 127 : 126;
+       return EXIT_SUCCESS;
 }
 
 static const char *
@@ -160,7 +162,7 @@ randreply(void)
        return replies[rand() % LEN(replies)];
 }
 
-static void
+static int
 dologin(struct passwd *pw)
 {
        char *term = getenv("TERM");
@@ -177,4 +179,6 @@ dologin(struct passwd *pw)
        if (chdir(pw->pw_dir) < 0)
                eprintf("chdir %s:", pw->pw_dir);
        execlp(pw->pw_shell, pw->pw_shell, "-l", NULL);
+       weprintf("execlp %s:", pw->pw_shell);
+       return (errno == ENOENT) ? 127 : 126;
 }