pwdx: re-create invalid process id check

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

diff --git a/pwdx.c b/pwdx.c
index 2743040a191bdee91e10a2001910cf2032c9954b..b4aa689c635ea2653a17678263f742d7a036cb48 100644 (file)
--- a/pwdx.c
+++ b/pwdx.c
@@ -35,6 +35,23 @@ static void __attribute__ ((__noreturn__)) usage(FILE * out)
        exit(out == stderr ? EXIT_FAILURE : EXIT_SUCCESS);
 }
 
+int check_pid_argument(char *input)
+{
+       int skip = 0;
+       long pid;
+       char *end = NULL;
+
+       if (!strncmp("/proc/", input, 6))
+               skip = 6;
+       pid = strtol(input + skip, &end, 10);
+
+       if (errno || input + skip == end || (end && *end))
+               return 1;
+       if (pid < 1)
+               return 1;
+       return 0;
+}
+
 int main(int argc, char *argv[])
 {
        char ch;
@@ -78,6 +95,9 @@ int main(int argc, char *argv[])
                /* Constant 10 is the length of strings "/proc/" + "/cwd" + 1 */
                char buf[10 + strlen(argv[i]) + 1];
 
+               if (check_pid_argument(argv[i]))
+                       errx(EXIT_FAILURE, _("invalid process id: %s"),
+                            argv[i]);
                /*
                 * At this point, all arguments are in the form
                 * /proc/NNNN or NNNN, so a simple check based on