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authorGravatar Denis Vlasenko <vda.linux@googlemail.com>2007-08-15 20:05:37 +0000
committerGravatar Denis Vlasenko <vda.linux@googlemail.com>2007-08-15 20:05:37 +0000
commitbb23c069191f18ed11b826371ed3571e214b41e3 (patch)
tree8a7afbb2ead270f08c3fa4741da0522418142787
parent9f7b92a2e13b184b1d6f7d9fbddc133666224bcf (diff)
downloadbusybox-bb23c069191f18ed11b826371ed3571e214b41e3.tar.gz
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if pidfile turned out to be !regular file, do not unlink it.
It's most probably the /dev/null.
-rw-r--r--Config.in2
-rw-r--r--include/libbb.h12
-rw-r--r--libbb/pidfile.c24
-rw-r--r--networking/udhcp/dhcpc.c2
4 files changed, 25 insertions, 15 deletions
diff --git a/Config.in b/Config.in
index 54bcd9d10..24e461eb7 100644
--- a/Config.in
+++ b/Config.in
@@ -144,7 +144,7 @@ config FEATURE_PIDFILE
bool "Support writing pidfiles"
default n
help
- This option makes some applets (crond, syslogd and inetd) write
+ This option makes some applets (e.g. crond, syslogd, inetd) write
a pidfile in /var/run. Some applications rely on them.
config FEATURE_SUID
diff --git a/include/libbb.h b/include/libbb.h
index fc0a0ae6c..d60b410ae 100644
--- a/include/libbb.h
+++ b/include/libbb.h
@@ -622,12 +622,14 @@ llist_t *llist_rev(llist_t *list);
/* start_stop_daemon and udhcpc are special - they want
* to create pidfiles regardless of FEATURE_PIDFILE */
#if ENABLE_FEATURE_PIDFILE || defined(WANT_PIDFILE)
-int write_pidfile(const char *path);
-#define remove_pidfile(f) ((void)unlink(f))
+/* True only if we created pidfile which is *file*, not /dev/null etc */
+extern smallint wrote_pidfile;
+void write_pidfile(const char *path);
+#define remove_pidfile(path) do { if (wrote_pidfile) unlink(path); } while (0)
#else
-/* Why? #defining it to 1 gives "warning: statement with no effect"... */
-static ALWAYS_INLINE int write_pidfile(const char *path) { return 1; }
-#define remove_pidfile(f) ((void)0)
+enum { wrote_pidfile = 0 };
+#define write_pidfile(path) ((void)0)
+#define remove_pidfile(path) ((void)0)
#endif
enum {
diff --git a/libbb/pidfile.c b/libbb/pidfile.c
index 64e67c322..cafa7891f 100644
--- a/libbb/pidfile.c
+++ b/libbb/pidfile.c
@@ -11,22 +11,30 @@
#define WANT_PIDFILE 1
#include "libbb.h"
-int write_pidfile(const char *path)
+smallint wrote_pidfile;
+
+void write_pidfile(const char *path)
{
int pid_fd;
char *end;
char buf[sizeof(int)*3 + 2];
+ struct stat sb;
if (!path)
- return 1;
+ return;
/* we will overwrite stale pidfile */
pid_fd = open(path, O_WRONLY|O_CREAT|O_TRUNC, 0666);
if (pid_fd < 0)
- return 0;
- /* few bytes larger, but doesn't use stdio */
- end = utoa_to_buf(getpid(), buf, sizeof(buf));
- *end = '\n';
- full_write(pid_fd, buf, end - buf + 1);
+ return;
+
+ /* path can be "/dev/null"! Test for such cases */
+ wrote_pidfile = (fstat(pid_fd, &sb) == 0) && S_ISREG(sb.st_mode);
+
+ if (wrote_pidfile) {
+ /* few bytes larger, but doesn't use stdio */
+ end = utoa_to_buf(getpid(), buf, sizeof(buf));
+ *end = '\n';
+ full_write(pid_fd, buf, end - buf + 1);
+ }
close(pid_fd);
- return 1;
}
diff --git a/networking/udhcp/dhcpc.c b/networking/udhcp/dhcpc.c
index 7cb1dfe5d..7d38742b9 100644
--- a/networking/udhcp/dhcpc.c
+++ b/networking/udhcp/dhcpc.c
@@ -546,7 +546,7 @@ int udhcpc_main(int argc, char **argv)
ret0:
retval = 0;
ret:
- if (client_config.pidfile)
+ /*if (client_config.pidfile) - remove_pidfile has it's own check */
remove_pidfile(client_config.pidfile);
return retval;
}