Re: [hackers] [slock] Use argv0 instead of passing "slock:" to die every time || FRIGN
On 14 February 2016 at 02:14, wrote: > commit b02c4d452a7942d4be3c69e6f98dafd35a2e4e78 > Author: FRIGN > AuthorDate: Sun Feb 14 02:13:54 2016 +0100 > Commit: FRIGN > CommitDate: Sun Feb 14 02:13:54 2016 +0100 > > Use argv0 instead of passing "slock:" to die every time > > diff --git a/slock.c b/slock.c > index 4531f95..a0ffed0 100644 > --- a/slock.c > +++ b/slock.c > @@ -46,6 +46,7 @@ static Bool failure = False; > static Bool rr; > static int rrevbase; > static int rrerrbase; > +static char *argv0; > > static void > die(const char *errstr, ...) > @@ -53,6 +54,7 @@ die(const char *errstr, ...) > va_list ap; > > va_start(ap, errstr); > + fprintf(stderr, "%s: ", argv0); I don't like this approach. Code should always output the original name of the program, not the name of the process. When someone renames slock into foo, then I cannot assert anymore what it really is all about, if I query ./foo -v or ./foo -h I'm for reverting to the original approach here -- btw. same for all other suckless tools. BR, Anselm
Re: [hackers] [slock] Use argv0 instead of passing "slock:" to die every time || FRIGN
On Mon, Feb 15, 2016 at 11:37:15AM +0100, FRIGN wrote: > On Mon, 15 Feb 2016 10:34:15 + > Dimitris Papastamos wrote: > > Hey Dimitris, > > > Yes this pattern is used in sbase. There is no point however > > replicating it to other projects. > > so how would you approach this? If slock was only a main()-function, > one could've thought to just pass argv[0] to each call of die. > But it is not. > > Would your approach be to just set argv0 as argv[0] and carry on > without modifying argc, argv? > I was surprised this idiomatic one-liner has received such opposition. The code was fine as it was.
Re: [hackers] [slock] Use argv0 instead of passing "slock:" to die every time || FRIGN
FRIGN wrote: > we came up with this in sbase/ubase as an idiomatic way to set argv0 > for tools that don't use arg.h. > We need argv0 here because I moved the prepending of the argv[0] into > die(), and thus we need to store the argv0 in a global variable. Heyho frign, sure, but I asked why you would *shift* argc and argv right at the start of main. If someone reads just the fork exec part and assumes argv[0] is `slock`, this is confusing and forcing the reader to search for the place where argv is changed. --Markus
Re: [hackers] [slock] Use argv0 instead of passing "slock:" to die every time || FRIGN
On Mon, 15 Feb 2016 10:34:15 + Dimitris Papastamos wrote: Hey Dimitris, > Yes this pattern is used in sbase. There is no point however > replicating it to other projects. so how would you approach this? If slock was only a main()-function, one could've thought to just pass argv[0] to each call of die. But it is not. Would your approach be to just set argv0 as argv[0] and carry on without modifying argc, argv? I was surprised this idiomatic one-liner has received such opposition. Cheers FRIGN -- FRIGN
Re: [hackers] [slock] Use argv0 instead of passing "slock:" to die every time || FRIGN
On Mon, Feb 15, 2016 at 11:30:59AM +0100, FRIGN wrote: > On Mon, 15 Feb 2016 11:22:08 +0100 > Markus Teich wrote: > > Hey Markus, > > > why this `argc--, argv++` shenanigans? I think it's more confusing rather > > than > > helping. > > we came up with this in sbase/ubase as an idiomatic way to set argv0 > for tools that don't use arg.h. > We need argv0 here because I moved the prepending of the argv[0] into > die(), and thus we need to store the argv0 in a global variable. Yes this pattern is used in sbase. There is no point however replicating it to other projects.
Re: [hackers] [slock] Use argv0 instead of passing "slock:" to die every time || FRIGN
On Mon, 15 Feb 2016 11:22:08 +0100 Markus Teich wrote: Hey Markus, > why this `argc--, argv++` shenanigans? I think it's more confusing rather than > helping. we came up with this in sbase/ubase as an idiomatic way to set argv0 for tools that don't use arg.h. We need argv0 here because I moved the prepending of the argv[0] into die(), and thus we need to store the argv0 in a global variable. Cheers FRIGN -- FRIGN
Re: [hackers] [slock] Use argv0 instead of passing "slock:" to die every time || FRIGN
g...@suckless.org wrote:
> + argv0 = argv[0], argc--, argv++;
> - if (argc >= 2 && fork() == 0) {
> + if (argc >= 1 && fork() == 0) {
> if (dpy)
> close(ConnectionNumber(dpy));
> - execvp(argv[1], argv+1);
> - die("slock: execvp %s failed: %s\n", argv[1], strerror(errno));
> + execvp(argv[0], argv);
> + die("execvp %s failed: %s\n", argv[0], strerror(errno));
Heyho frign,
why this `argc--, argv++` shenanigans? I think it's more confusing rather than
helping.
--Markus
[hackers] [slock] Use argv0 instead of passing "slock:" to die every time || FRIGN
commit b02c4d452a7942d4be3c69e6f98dafd35a2e4e78
Author: FRIGN
AuthorDate: Sun Feb 14 02:13:54 2016 +0100
Commit: FRIGN
CommitDate: Sun Feb 14 02:13:54 2016 +0100
Use argv0 instead of passing "slock:" to die every time
diff --git a/slock.c b/slock.c
index 4531f95..a0ffed0 100644
--- a/slock.c
+++ b/slock.c
@@ -46,6 +46,7 @@ static Bool failure = False;
static Bool rr;
static int rrevbase;
static int rrerrbase;
+static char *argv0;
static void
die(const char *errstr, ...)
@@ -53,6 +54,7 @@ die(const char *errstr, ...)
va_list ap;
va_start(ap, errstr);
+ fprintf(stderr, "%s: ", argv0);
vfprintf(stderr, errstr, ap);
va_end(ap);
exit(1);
@@ -88,9 +90,9 @@ getpw(void)
errno = 0;
if (!(pw = getpwuid(getuid( {
if (errno)
- die("slock: getpwuid: %s\n", strerror(errno));
+ die("getpwuid: %s\n", strerror(errno));
else
- die("slock: cannot retrieve password entry\n");
+ die("cannot retrieve password entry\n");
}
rval = pw->pw_passwd;
@@ -98,7 +100,7 @@ getpw(void)
if (rval[0] == 'x' && rval[1] == '\0') {
struct spwd *sp;
if (!(sp = getspnam(getenv("USER"
- die("slock: cannot retrieve shadow entry (make sure to
suid or sgid slock)\n");
+ die("cannot retrieve shadow entry (make sure to suid or
sgid slock)\n");
rval = sp->sp_pwdp;
}
#endif
@@ -106,7 +108,7 @@ getpw(void)
/* drop privileges */
if (geteuid() == 0 &&
((getegid() != pw->pw_gid && setgid(pw->pw_gid) < 0) ||
setuid(pw->pw_uid) < 0))
- die("slock: cannot drop privileges\n");
+ die("cannot drop privileges\n");
return rval;
}
#endif
@@ -254,7 +256,7 @@ lockscreen(Display *dpy, int screen)
usleep(1000);
}
if (!len) {
- fprintf(stderr, "slock: unable to grab mouse pointer for screen
%d\n", screen);
+ fprintf(stderr, "unable to grab mouse pointer for screen %d\n",
screen);
} else {
for (len = 1000; len; len--) {
if (XGrabKeyboard(dpy, lock->root, True, GrabModeAsync,
GrabModeAsync, CurrentTime) == GrabSuccess) {
@@ -264,7 +266,7 @@ lockscreen(Display *dpy, int screen)
}
usleep(1000);
}
- fprintf(stderr, "slock: unable to grab keyboard for screen
%d\n", screen);
+ fprintf(stderr, "unable to grab keyboard for screen %d\n",
screen);
}
/* grabbing one of the inputs failed */
running = 0;
@@ -281,24 +283,26 @@ main(int argc, char **argv)
Display *dpy;
int screen;
+ argv0 = argv[0], argc--, argv++;
+
#ifdef __linux__
dontkillme();
#endif
if (!getpwuid(getuid()))
- die("slock: no passwd entry for you\n");
+ die("no passwd entry for you\n");
#ifndef HAVE_BSD_AUTH
pws = getpw();
#endif
if (!(dpy = XOpenDisplay(0)))
- die("slock: cannot open display\n");
+ die("cannot open display\n");
rr = XRRQueryExtension(dpy, &rrevbase, &rrerrbase);
/* Get the number of screens in display "dpy" and blank them all. */
nscreens = ScreenCount(dpy);
if (!(locks = malloc(sizeof(Lock*) * nscreens)))
- die("slock: malloc: %s\n", strerror(errno));
+ die("Out of memory.\n");
int nlocks = 0;
for (screen = 0; screen < nscreens; screen++) {
if ((locks[screen] = lockscreen(dpy, screen)) != NULL)
@@ -313,11 +317,11 @@ main(int argc, char **argv)
return 1;
}
- if (argc >= 2 && fork() == 0) {
+ if (argc >= 1 && fork() == 0) {
if (dpy)
close(ConnectionNumber(dpy));
- execvp(argv[1], argv+1);
- die("slock: execvp %s failed: %s\n", argv[1], strerror(errno));
+ execvp(argv[0], argv);
+ die("execvp %s failed: %s\n", argv[0], strerror(errno));
}
/* Everything is now blank. Now wait for the correct password. */
