Added switch for printing only succeeding syscalls.

ChangeLog

@@ -1,3 +1,12 @@
+2002-11-06  Michal Ludvig  <mludvig@suse.cz>
+
+	From Marty Leisner <leisner@rochester.rr.com>, 
+	rewritten my mludvig:
+	* strace.c (not_failing_only): New.
+	(usage): Added -z switch description.
+	(main): Added -z switch parsing to not_failing_only variable.
+	* syscall.c (trace_syscall): Added not_failing_only handling.
+
 2002-10-08  Heiko Carstens <heiko.carstens@de.ibm.com>
 
 	Missing complete changelog for 2002-10-07 commit:

defs.h

@@ -553,3 +553,5 @@ do {									\
 #ifdef IA64
 extern long ia32;
 #endif
+
+extern int not_failing_only;

strace.c

@@ -67,6 +67,9 @@ int rflag = 0, tflag = 0, dtime = 0, cflag = 0;
 int iflag = 0, xflag = 0, qflag = 0;
 int pflag_seen = 0;
 
+/* Sometimes we want to print only succeeding syscalls. */
+int not_failing_only = 0;
+
 char *username = NULL;
 uid_t run_uid;
 gid_t run_gid;
@@ -154,6 +157,7 @@ usage: strace [-dffhiqrtttTvVxx] [-a column] [-e expr] ... [-o file]\n\
 -s strsize -- limit length of print strings to STRSIZE chars (default %d)\n\
 -S sortby -- sort syscall counts by: time, calls, name, nothing (default %s)\n\
 -u username -- run command as username handling setuid and/or setgid\n\
+-z -- print only succeeding syscalls\n\
 ", DEFAULT_ACOLUMN, DEFAULT_STRLEN, DEFAULT_SORTBY);
 	exit(exitval);
 }
@@ -190,7 +194,7 @@ char *argv[];
 	set_sortby(DEFAULT_SORTBY);
 	set_personality(DEFAULT_PERSONALITY);
 	while ((c = getopt(argc, argv,
-		"+cdfFhiqrtTvVxa:e:o:O:p:s:S:u:")) != EOF) {
+		"+cdfFhiqrtTvVxza:e:o:O:p:s:S:u:")) != EOF) {
 		switch (c) {
 		case 'c':
 			cflag++;
@@ -234,6 +238,9 @@ char *argv[];
 			printf("%s\n", version);
 			exit(0);
 			break;
+		case 'z':
+			not_failing_only = 1;
+			break;
 		case 'a':
 			acolumn = atoi(optarg);
 			break;

syscall.c

@@ -1742,8 +1742,11 @@ struct tcb *tcp;
 		if (tcp->scno >= nsyscalls || tcp->scno < 0
 		    || (qual_flags[tcp->scno] & QUAL_RAW))
 			sys_res = printargs(tcp);
-		else
+		else {
+			if (not_failing_only && tcp->u_error)
+				return;	/* ignore failed syscalls */
 			sys_res = (*sysent[tcp->scno].sys_func)(tcp);
+		}	
 		u_error = tcp->u_error;
 		tprintf(") ");
 		tabto(acolumn);