lib/process: Add add_stderr flag to process module

For some process execution functions, we'd like to capture stderr as
well as stdout. Currently, we unconditionally redirect subprocess stderr
to the petitboot log file.

This change adds an add_stderr flag to struct process, which indicates
to the process library that we want stderr as well as stdout. If this is
specified, the subprocess' stderr is captured to stdout_buf.

Signed-off-by: Jeremy Kerr <jk@ozlabs.org>

1 files changed, 57 insertions, 0 deletions

diff --git a/test/lib/test-process-stderr-stdout.c b/test/lib/test-process-stderr-stdout.c
new file mode 100644
index 0000000..3192306
--- /dev/null
+++ b/test/lib/test-process-stderr-stdout.c
@@ -0,0 +1,57 @@
+
+#include <stdlib.h>
+#include <string.h>
+#include <assert.h>
+
+#include <process/process.h>
+#include <waiter/waiter.h>
+#include <talloc/talloc.h>
+
+static int do_child(void)
+{
+	fprintf(stderr, "forty ");
+	fflush(stderr);
+	fprintf(stdout, "two\n");
+	fflush(stdout);
+	return 42;
+}
+
+int main(int argc, char **argv)
+{
+	struct waitset *waitset;
+	struct process *process;
+	const char *child_argv[3];
+	void *ctx;
+
+	if (argc == 2 && !strcmp(argv[1], "child"))
+		return do_child();
+
+	ctx = talloc_new(NULL);
+
+	waitset = waitset_create(ctx);
+
+	process_init(ctx, waitset, false);
+
+	child_argv[0] = argv[0];
+	child_argv[1] = "child";
+	child_argv[2] = NULL;
+
+	process = process_create(ctx);
+	process->path = child_argv[0];
+	process->argv = child_argv;
+	process->keep_stdout = true;
+	process->add_stderr = true;
+
+	process_run_sync(process);
+
+	assert(WIFEXITED(process->exit_status));
+	assert(WEXITSTATUS(process->exit_status) == 42);
+
+	assert(process->stdout_len == strlen("forty two\n"));
+	assert(!memcmp(process->stdout_buf, "forty two\n",
+				process->stdout_len));
+
+	talloc_free(ctx);
+
+	return EXIT_SUCCESS;
+}