trace-cmd utest: Separate out the grep and pipes

To make the grep and pipe functions in the unit test more flexible,
separate them out and instead of passing in the arguments and using
va_list directly, pass in a void pointer and use as structure to pass in
the arguments. This will allow for extending the grep and pipe functions
to use different type of arguments as well as functionality.

Link: https://lore.kernel.org/linux-trace-devel/20221115205355.2580214-4-rostedt@goodmis.org

Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>

1 files changed, 95 insertions, 17 deletions

diff --git a/utest/tracecmd-utest.c b/utest/tracecmd-utest.c
index 2ec3f711..88d72177 100644
--- a/utest/tracecmd-utest.c
+++ b/utest/tracecmd-utest.c
@@ -10,6 +10,7 @@
 #include <time.h>
 #include <dirent.h>
 #include <unistd.h>
+#include <ctype.h>
 #include <sys/stat.h>
 #include <sys/wait.h>
 #include <sys/types.h>
@@ -111,9 +112,9 @@ static int run_trace(const char *cmd, ...)
 	return ret;
 }
 
-static int pipe_it(int *ofd, int *efd, const char *cmd, va_list ap)
+static int pipe_it(int *ofd, int *efd, int (*func)(void *),
+		   void *data)
 {
-	char **argv;
 	int obrass[2];
 	int ebrass[2];
 	pid_t pid;
@@ -130,9 +131,6 @@ static int pipe_it(int *ofd, int *efd, const char *cmd, va_list ap)
 		goto fail;
 
 	if (!pid) {
-		argv = get_args(cmd, ap);
-		if (!argv)
-			exit(-1);
 
 		close(obrass[0]);
 		close(STDOUT_FILENO);
@@ -144,7 +142,7 @@ static int pipe_it(int *ofd, int *efd, const char *cmd, va_list ap)
 		if (dup2(obrass[1], STDERR_FILENO) < 0)
 			exit(-1);
 
-		ret = execvp(tracecmd_exec, argv);
+		ret = func(data);
 		exit(ret);
 	}
 
@@ -165,26 +163,52 @@ static int pipe_it(int *ofd, int *efd, const char *cmd, va_list ap)
 	return -1;
 }
 
-static int grep_it(const char *match, const char *cmd, ...)
+struct do_grep {
+	const char		*cmd;
+	va_list			*ap;
+};
+
+static int do_grep(void *data)
+{
+	struct do_grep *gdata = data;
+	char **argv;
+	int ret;
+
+	argv = get_args(gdata->cmd, *gdata->ap);
+	if (!argv)
+		exit(-1);
+
+	ret = execvp(tracecmd_exec, argv);
+	tracefs_list_free(argv);
+	return ret;
+}
+
+struct do_grep_it {
+	const char		*match;
+	const char		*cmd;
+	va_list			*ap;
+};
+
+static int do_grep_it(void *data)
 {
+	struct do_grep_it *dgdata = data;
+	struct do_grep gdata;
 	FILE *fp;
 	regex_t reg;
-	va_list ap;
 	char *buf = NULL;
 	ssize_t n;
 	size_t l = 0;
-	bool found = false;
 	int ofd;
 	int efd;
 	int pid;
 	int ret;
 
-	if (regcomp(&reg, match, REG_ICASE|REG_NOSUB))
+	if (regcomp(&reg, dgdata->match, REG_ICASE|REG_NOSUB))
 		return -1;
 
-	va_start(ap, cmd);
-	pid = pipe_it(&ofd, &efd, cmd, ap);
-	va_end(ap);
+	gdata.cmd = dgdata->cmd;
+	gdata.ap = dgdata->ap;
+	pid = pipe_it(&ofd, &efd, do_grep, &gdata);
 
 	if (pid < 0) {
 		regfree(&reg);
@@ -197,10 +221,65 @@ static int grep_it(const char *match, const char *cmd, ...)
 
 	do {
 		n = getline(&buf, &l, fp);
-		if (show_output && n > 0)
-			printf("%s", buf);
 		if (n > 0 && regexec(&reg, buf, 0, NULL, 0) == 0)
+			printf("%s", buf);
+	} while (n >= 0);
+
+	free(buf);
+ out:
+	ret = wait_for_exec(pid);
+	if (fp)
+		fclose(fp);
+	else
+		perror("fp");
+	close(ofd);
+	close(efd);
+	regfree(&reg);
+
+	return ret > 0 ? 0 : ret;
+}
+
+struct do_grep_match {
+	const char		*match;
+	const char		*cmd;
+	va_list			*ap;
+};
+
+static int grep_match(const char *match, const char *cmd, ...)
+{
+	struct do_grep_it gdata;
+	FILE *fp;
+	va_list ap;
+	char *buf = NULL;
+	ssize_t n;
+	size_t l = 0;
+	bool found = false;
+	int ofd;
+	int efd;
+	int pid;
+	int ret;
+
+	va_start(ap, cmd);
+	gdata.match = match;
+	gdata.cmd = cmd;
+	gdata.ap = &ap;
+	pid = pipe_it(&ofd, &efd, do_grep_it, &gdata);
+	va_end(ap);
+
+	if (pid < 0)
+		return -1;
+
+	fp = fdopen(ofd, "r");
+	if (!fp)
+		goto out;
+
+	do {
+		n = getline(&buf, &l, fp);
+		if (n > 0) {
+			if (show_output)
+				printf("%s", buf);
 			found = true;
+		}
 	} while (n >= 0);
 
 	free(buf);
@@ -215,7 +294,6 @@ static int grep_it(const char *match, const char *cmd, ...)
 		close(ofd);
 	}
 	close(efd);
-	regfree(&reg);
 
 	return found ? 0 : 1;
 }
@@ -240,7 +318,7 @@ static void test_trace_convert6(void)
 		ret = run_trace("record", TRACECMD_OUT, "-e", "sched", "sleep", "1", NULL);
 		CU_TEST(ret == 0);
 	}
-	ret = grep_it("[ \t]6[ \t]*\\[Version\\]", "dump", TRACECMD_IN2, NULL);
+	ret = grep_match("[ \t]6[ \t]*\\[Version\\]", "dump", TRACECMD_IN2, NULL);
 	CU_TEST(ret == 0);
 }