Fix PID prefix printing in "strace -oLOG -ff -p1 -p2 -p3" case
In this case we were printing PIDs to LOG.* files
even though it is not necessary.
The fix is in the addition of "&& followfork < 2" condition.
* strace.c: Remove pflag_seen variable, add print_pid_pfx one.
(process_opt_p_list): Do not pflag_seen++.
(main): Use "nprocs != 0" condition instead of "pflag_seen != 0".
Set print_pid_pfx before entering main tracing loop.
(printleader): Use print_pid_pfx to decide whether to print pid prefix.
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
diff --git a/strace.c b/strace.c
index 5e2f9c6..e627a5e 100644
--- a/strace.c
+++ b/strace.c
@@ -72,7 +72,8 @@
static unsigned int syscall_trap_sig = SIGTRAP;
int dtime = 0, xflag = 0, qflag = 0;
cflag_t cflag = CFLAG_NONE;
-static int iflag = 0, pflag_seen = 0, rflag = 0, tflag = 0;
+static int iflag = 0, rflag = 0, tflag = 0;
+static int print_pid_pfx = 0;
/* -I n */
enum {
@@ -447,12 +448,6 @@
*delim = c;
tcp = alloc_tcb(pid, 0);
tcp->flags |= TCB_ATTACHED;
- /*
- * pflag_seen says how many PIDs we handled,
- * not how many -p opts there were.
- * Used to decide whether to print pid prefix in logs.
- */
- pflag_seen++;
if (c == '\0')
break;
opt = delim + 1;
@@ -1210,10 +1205,10 @@
acolumn_spaces[acolumn] = '\0';
/* Must have PROG [ARGS], or -p PID. Not both. */
- if (!argv[0] == !pflag_seen)
+ if (!argv[0] == !nprocs)
usage(stderr, 1);
- if (pflag_seen && daemonized_tracer) {
+ if (nprocs != 0 && daemonized_tracer) {
error_msg_and_die("-D and -p are mutually exclusive options");
}
@@ -1331,9 +1326,16 @@
sa.sa_handler = SIG_DFL;
sigaction(SIGCHLD, &sa, NULL);
- if (pflag_seen || daemonized_tracer)
+ if (nprocs != 0 || daemonized_tracer)
startup_attach();
+ /* Do we want pids printed in our -o OUTFILE?
+ * -ff: no (every pid has its own file); or
+ * -f: yes (there can be more pids in the future); or
+ * -p PID1,PID2: yes (there are already more than one pid)
+ */
+ print_pid_pfx = (outfname && followfork < 2 && (followfork == 1 || nprocs > 1));
+
if (trace() < 0)
exit(1);
@@ -2094,10 +2096,12 @@
printing_tcp = tcp;
curcol = 0;
- if ((followfork == 1 || pflag_seen > 1) && outfname)
+
+ if (print_pid_pfx)
tprintf("%-5d ", tcp->pid);
else if (nprocs > 1 && !outfname)
tprintf("[pid %5u] ", tcp->pid);
+
if (tflag) {
char str[sizeof("HH:MM:SS")];
struct timeval tv, dtv;