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authorGravatar Denis Vlasenko <vda.linux@googlemail.com>2008-02-19 18:26:40 +0000
committerGravatar Denis Vlasenko <vda.linux@googlemail.com>2008-02-19 18:26:40 +0000
commit624188aec0e730375bb782a45ab3224b33dd30e9 (patch)
tree64a7f24d94f6ef3cb883b54ac3196bda160278a4 /miscutils/microcom.c
parent671ca33aa1804c1c4e26bf83635206dce7ed2623 (diff)
downloadbusybox-624188aec0e730375bb782a45ab3224b33dd30e9.tar.gz
busybox-624188aec0e730375bb782a45ab3224b33dd30e9.tar.bz2
microcom: tiny shrink, adding comments
Diffstat (limited to 'miscutils/microcom.c')
-rw-r--r--miscutils/microcom.c15
1 files changed, 8 insertions, 7 deletions
diff --git a/miscutils/microcom.c b/miscutils/microcom.c
index ea48291ae..3c573eaa9 100644
--- a/miscutils/microcom.c
+++ b/miscutils/microcom.c
@@ -51,18 +51,17 @@ int microcom_main(int argc, char **argv)
enum {
OPT_X = 1 << 0, // do not respect Ctrl-X, Ctrl-@
OPT_s = 1 << 1, // baudrate
- OPT_d = 1 << 2, // wait for device response, msecs
+ OPT_d = 1 << 2, // wait for device response, ms
OPT_t = 1 << 3, // timeout, ms
};
speed_t speed = 9600;
int delay = -1;
int timeout = -1;
+ unsigned opts;
// fetch options
- unsigned opts;
- opt_complementary = "=1:s+:d+:t+"; // exactly one arg should be there
+ opt_complementary = "=1:s+:d+:t+"; // exactly one arg, numeric options
opts = getopt32(argv, "Xs:d:t:", &speed, &delay, &timeout);
-
// argc -= optind;
argv += optind;
@@ -71,14 +70,16 @@ int microcom_main(int argc, char **argv)
device_lock_file = xasprintf("/var/lock/LCK..%s", device_lock_file);
sfd = open(device_lock_file, O_CREAT | O_WRONLY | O_TRUNC | O_EXCL, 0644);
if (sfd < 0) {
+ // device already locked -> bail out
if (errno == EEXIST)
bb_perror_msg_and_die("can't create %s", device_lock_file);
+ // can't create lock -> don't care
if (ENABLE_FEATURE_CLEAN_UP)
free(device_lock_file);
device_lock_file = NULL;
- }
- if (sfd > 0) {
- // %4d to make mgetty happy. It treats 4-bytes lock files as binary,
+ } else {
+ // %4d to make concurrent mgetty (if any) happy.
+ // Mgetty treats 4-bytes lock files as binary,
// not text, PID. Making 5+ char file. Brrr...
char *s = xasprintf("%4d\n", getpid());
write(sfd, s, strlen(s));