Refactor main() - slock - simple X display locker utility
(HTM) git clone git://git.suckless.org/slock
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---
(DIR) commit 3bb868e40873c568acdec74f7783c77f063aa396
(DIR) parent a7afade1701a809f6a33b53525d59dd29b38d381
(HTM) Author: FRIGN <dev@frign.de>
Date: Mon, 22 Aug 2016 00:25:21 +0200
Refactor main()
- Add arg.h and fix usage
Given slock is suid we don't want to have half-measures in place to
parse the arguments in case the code is changed in the future with
somebody not paying enough attention.
Also, fix the usage string output to be more consistent across the
suckless toolbase and make it reflect the manpage entry.
- Comments
Use proper block comments and add/change them where necessary
to help in studying the code.
- Error messages
Consistently prepend them with "slock:" and fix wording and
do a proper cleanup before quitting (XCloseDisplay and free
the locks), making the die() semantics consistent with st's.
- getpwuid() error reporting
Properly present an error message if getpwuid() fails.
- fork() error reporting
Properly present an error message if fork() fails. If we cannot
close the connection within the fork context we abort the
operation and report an error.
- execvp() error handling
If execvp fails, we cannot call die() afterwards as this implies
calling exit(). We must use _exit() to prevent the libc from
doing now "illegal" cleanup-work.
Diffstat:
A arg.h | 65 +++++++++++++++++++++++++++++++
M slock.c | 85 ++++++++++++++++++++-----------
2 files changed, 119 insertions(+), 31 deletions(-)
---
(DIR) diff --git a/arg.h b/arg.h
@@ -0,0 +1,65 @@
+/*
+ * Copy me if you can.
+ * by 20h
+ */
+
+#ifndef ARG_H__
+#define ARG_H__
+
+extern char *argv0;
+
+/* use main(int argc, char *argv[]) */
+#define ARGBEGIN for (argv0 = *argv, argv++, argc--;\
+ argv[0] && argv[0][0] == '-'\
+ && argv[0][1];\
+ argc--, argv++) {\
+ char argc_;\
+ char **argv_;\
+ int brk_;\
+ if (argv[0][1] == '-' && argv[0][2] == '\0') {\
+ argv++;\
+ argc--;\
+ break;\
+ }\
+ for (brk_ = 0, argv[0]++, argv_ = argv;\
+ argv[0][0] && !brk_;\
+ argv[0]++) {\
+ if (argv_ != argv)\
+ break;\
+ argc_ = argv[0][0];\
+ switch (argc_)
+
+/* Handles obsolete -NUM syntax */
+#define ARGNUM case '0':\
+ case '1':\
+ case '2':\
+ case '3':\
+ case '4':\
+ case '5':\
+ case '6':\
+ case '7':\
+ case '8':\
+ case '9'
+
+#define ARGEND }\
+ }
+
+#define ARGC() argc_
+
+#define ARGNUMF() (brk_ = 1, estrtonum(argv[0], 0, INT_MAX))
+
+#define EARGF(x) ((argv[0][1] == '\0' && argv[1] == NULL)?\
+ ((x), abort(), (char *)0) :\
+ (brk_ = 1, (argv[0][1] != '\0')?\
+ (&argv[0][1]) :\
+ (argc--, argv++, argv[0])))
+
+#define ARGF() ((argv[0][1] == '\0' && argv[1] == NULL)?\
+ (char *)0 :\
+ (brk_ = 1, (argv[0][1] != '\0')?\
+ (&argv[0][1]) :\
+ (argc--, argv++, argv[0])))
+
+#define LNGARG() &argv[0][0]
+
+#endif
(DIR) diff --git a/slock.c b/slock.c
@@ -23,8 +23,11 @@
#include <bsd_auth.h>
#endif
+#include "arg.h"
#include "util.h"
+char *argv0;
+
enum {
INIT,
INPUT,
@@ -54,7 +57,6 @@ die(const char *errstr, ...)
{
va_list ap;
- fputs("slock: ", stderr);
va_start(ap, errstr);
vfprintf(stderr, errstr, ap);
va_end(ap);
@@ -280,8 +282,7 @@ lockscreen(Display *dpy, int screen)
static void
usage(void)
{
- fprintf(stderr, "usage: slock [-v|POST_LOCK_CMD]\n");
- exit(1);
+ die("usage: slock [-v | cmd [arg ...]]\n");
}
int
@@ -290,64 +291,86 @@ main(int argc, char **argv) {
const char *pws;
#endif
Display *dpy;
- int screen;
+ int s, nlocks;
- if ((argc >= 2) && !strcmp("-v", argv[1]))
- die("version %s, © 2006-2016 slock engineers\n", VERSION);
-
- /* treat first argument starting with a '-' as option */
- if ((argc >= 2) && argv[1][0] == '-')
+ ARGBEGIN {
+ case 'v':
+ fprintf(stderr, "slock-"VERSION"\n");
+ return 0;
+ default:
usage();
+ } ARGEND
#ifdef __linux__
dontkillme();
#endif
- if (!getpwuid(getuid()))
- die("no passwd entry for you\n");
+ /* Check if the current user has a password entry */
+ errno = 0;
+ if (!getpwuid(getuid())) {
+ if (errno == 0)
+ die("slock: no password entry for current user\n");
+ else
+ die("slock: getpwuid: %s\n", strerror(errno));
+ }
#ifndef HAVE_BSD_AUTH
pws = getpw();
#endif
- if (!(dpy = XOpenDisplay(0)))
- die("cannot open display\n");
+ if (!(dpy = XOpenDisplay(NULL)))
+ die("slock: cannot open display\n");
+
+ /* check for Xrandr support */
rr = XRRQueryExtension(dpy, &rrevbase, &rrerrbase);
- /* Get the number of screens in display "dpy" and blank them all. */
+
+ /* get number of screens in display "dpy" and blank them */
nscreens = ScreenCount(dpy);
- if (!(locks = malloc(sizeof(Lock*) * nscreens)))
- die("Out of memory.\n");
- int nlocks = 0;
- for (screen = 0; screen < nscreens; screen++) {
- if ((locks[screen] = lockscreen(dpy, screen)) != NULL)
+ if (!(locks = malloc(sizeof(Lock *) * nscreens))) {
+ XCloseDisplay(dpy);
+ die("slock: out of memory\n");
+ }
+ for (nlocks = 0, s = 0; s < nscreens; s++) {
+ if ((locks[s] = lockscreen(dpy, s)) != NULL)
nlocks++;
}
- XSync(dpy, False);
+ XSync(dpy, 0);
- /* Did we actually manage to lock something? */
- if (nlocks == 0) { /* nothing to protect */
+ /* did we actually manage to lock anything? */
+ if (nlocks == 0) {
+ /* nothing to protect */
free(locks);
XCloseDisplay(dpy);
return 1;
}
- if (argc >= 2 && fork() == 0) {
- if (dpy)
- close(ConnectionNumber(dpy));
- execvp(argv[1], argv+1);
- die("execvp %s failed: %s\n", argv[1], strerror(errno));
+ /* run post-lock command */
+ if (argc > 0) {
+ switch (fork()) {
+ case -1:
+ free(locks);
+ XCloseDisplay(dpy);
+ die("slock: fork failed: %s\n", strerror(errno));
+ case 0:
+ if (close(ConnectionNumber(dpy)) < 0)
+ die("slock: close: %s\n", strerror(errno));
+ execvp(argv[0], argv);
+ fprintf(stderr, "slock: execvp %s: %s\n", argv[0],
+ strerror(errno));
+ _exit(1);
+ }
}
- /* Everything is now blank. Now wait for the correct password. */
+ /* everything is now blank. Wait for the correct password */
#ifdef HAVE_BSD_AUTH
readpw(dpy);
#else
readpw(dpy, pws);
#endif
- /* Password ok, unlock everything and quit. */
- for (screen = 0; screen < nscreens; screen++)
- unlockscreen(dpy, locks[screen]);
+ /* password ok, unlock everything and quit */
+ for (s = 0; s < nscreens; s++)
+ unlockscreen(dpy, locks[s]);
free(locks);
XCloseDisplay(dpy);