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>

diff --git a/lib/process/process.c b/lib/process/process.c
index 1a16fb6312b4fb74dc8cc753806009e939bd7691..3c81b29340f8ae69ccd99f4ebe10133eb408e47d 100644 (file)
--- a/lib/process/process.c
+++ b/lib/process/process.c
@@ -125,7 +125,10 @@ static void process_setup_stdout_child(struct process_info *procinfo)
        else
                dup2(log, STDOUT_FILENO);
 
-       dup2(log, STDERR_FILENO);
+       if (procinfo->process.keep_stdout && procinfo->process.add_stderr)
+               dup2(procinfo->stdout_pipe[1], STDERR_FILENO);
+       else
+               dup2(log, STDERR_FILENO);
 }
 
 static void process_finish_stdout(struct process_info *procinfo)

diff --git a/lib/process/process.h b/lib/process/process.h
index caeda92131327d862492ade1b65acbaa56348e9c..ae7fe32d06350679660ac21473b8cd45fa6fc986 100644 (file)
--- a/lib/process/process.h
+++ b/lib/process/process.h
@@ -31,6 +31,7 @@ struct process {
        const char              *path;
        const char              **argv;
        bool                    keep_stdout;
+       bool                    add_stderr;
        process_exit_cb         exit_cb;
        void                    *data;
 

diff --git a/test/lib/Makefile.am b/test/lib/Makefile.am
index 36067100553a09de2e7deec2e018f9fcd2b52dad..ae6027f80eb2ff933bcd332451f87eb7b2a7d773 100644 (file)
--- a/test/lib/Makefile.am
+++ b/test/lib/Makefile.am
@@ -26,6 +26,8 @@ check_PROGRAMS = list-test \
        test-process-noargs \
        test-process-sync \
        test-process-sync-stdout \
+       test-process-stderr \
+       test-process-stderr-stdout \
        test-process-async \
        test-process-async-stdout \
        test-process-parent-stdout \

diff --git a/test/lib/test-process-stderr-stdout.c b/test/lib/test-process-stderr-stdout.c
new file mode 100644 (file)
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;
+}

diff --git a/test/lib/test-process-stderr.c b/test/lib/test-process-stderr.c
new file mode 100644 (file)
index 0000000..a165caa
--- /dev/null
+++ b/test/lib/test-process-stderr.c
@@ -0,0 +1,54 @@
+
+#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 two\n");
+       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;
+}