[PATCH v2] inotifyd: -x: new option
Bartosz Golaszewski
bartekgola at gmail.com
Tue Aug 25 13:39:02 UTC 2015
Add -x option which allows to specify the exit status of PROG for which
inotifyd should exit.
An example use case for this change is writing parallel system startup
scripts with busybox' runit: inotifyd can be used to wait for a specific
pid-file to appear in /var/run and then exit, allowing the blocked script
to proceed.
function old new delta
inotifyd_main 653 742 +89
.rodata 157197 157261 +64
packed_usage 30460 30516 +56
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 3/0 up/down: 209/0) Total: 209 bytes
Signed-off-by: Bartosz Golaszewski <bartekgola at gmail.com>
---
v2:
- don't call xstrtol_range() if -x is not specified
v1:
http://lists.busybox.net/pipermail/busybox/2015-August/083219.html
miscutils/inotifyd.c | 26 ++++++++++++++++++++------
1 file changed, 20 insertions(+), 6 deletions(-)
diff --git a/miscutils/inotifyd.c b/miscutils/inotifyd.c
index 7a1a6a2..e142668 100644
--- a/miscutils/inotifyd.c
+++ b/miscutils/inotifyd.c
@@ -28,7 +28,7 @@
*/
//usage:#define inotifyd_trivial_usage
-//usage: "PROG FILE1[:MASK]..."
+//usage: "[OPTS] PROG FILE1[:MASK]..."
//usage:#define inotifyd_full_usage "\n\n"
//usage: "Run PROG on filesystem changes."
//usage: "\nWhen a filesystem event matching MASK occurs on FILEn,"
@@ -52,12 +52,17 @@
//usage: "\n n Subfile is created"
//usage: "\n d Subfile is deleted"
//usage: "\n"
+//usage: "\nOptions:"
+//usage: "\n -x STATUS Exit if PROG returns STATUS"
+//usage: "\n"
//usage: "\ninotifyd waits for PROG to exit."
//usage: "\nWhen x event happens for all FILEs, inotifyd exits."
#include "libbb.h"
#include <sys/inotify.h>
+#define OPT_x (1 << 0)
+
static const char mask_names[] ALIGN1 =
"a" // 0x00000001 File was accessed
"c" // 0x00000002 File was modified
@@ -84,17 +89,21 @@ enum {
int inotifyd_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int inotifyd_main(int argc, char **argv)
{
- int n;
- unsigned mask;
+ int n, exp_st, st;
+ unsigned mask, opts;
struct pollfd pfd;
char **watches; // names of files being watched
const char *args[5];
+ char *opt_x_str;
+
+ opts = getopt32(argv, "x:", &opt_x_str);
+ argc -= optind;
+ argv += optind;
// sanity check: agent and at least one watch must be given
- if (!argv[1] || !argv[2])
+ if (!argv[0] || !argv[1])
bb_show_usage();
- argv++;
// inotify_add_watch will number watched files
// starting from 1, thus watches[0] is unimportant,
// and 1st file name is watches[1].
@@ -190,7 +199,12 @@ int inotifyd_main(int argc, char **argv)
args[1] = events;
args[2] = watches[ie->wd];
args[3] = ie->len ? ie->name : NULL;
- spawn_and_wait((char **)args);
+ st = spawn_and_wait((char **)args);
+ if (opts & OPT_x) {
+ exp_st = xstrtol_range(opt_x_str, 10, 0, 255);
+ if (st == exp_st)
+ goto done;
+ }
}
// we are done if all files got final x event
if (ie->mask & 0x8000) {
--
2.1.4
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