Currently, the captured output (via `capture-output`) is segregated into separate GuestExecStatus fields (`out-data` and `err-data`). This means that downstream consumers have no way to reassemble the captured data back into the original stream.
This is relevant for chatty and semi-interactive (ie. read only) CLI tools. Such tools may deliberately interleave stdout and stderr for visual effect. If segregated, the output becomes harder to visually understand. This commit adds a new optional flag to the guest-exec qapi to merge the output streams such that consumers can have a pristine view of the original command output. Signed-off-by: Daniel Xu <d...@dxuuu.xyz> --- qga/commands.c | 13 ++++++++++++- qga/qapi-schema.json | 6 +++++- 2 files changed, 17 insertions(+), 2 deletions(-) diff --git a/qga/commands.c b/qga/commands.c index 360077364e..14b970e768 100644 --- a/qga/commands.c +++ b/qga/commands.c @@ -274,6 +274,15 @@ static void guest_exec_child_watch(GPid pid, gint status, gpointer data) /** Reset ignored signals back to default. */ static void guest_exec_task_setup(gpointer data) { + bool has_merge = *(bool *)data; + + if (has_merge) { + if (dup2(STDOUT_FILENO, STDERR_FILENO) != 0) { + slog("dup2() failed to merge stderr into stdout: %s", + strerror(errno)); + } + } + #if !defined(G_OS_WIN32) struct sigaction sigact; @@ -385,6 +394,7 @@ GuestExec *qmp_guest_exec(const char *path, bool has_env, strList *env, const char *input_data, bool has_capture_output, bool capture_output, + bool has_merge_output, bool merge_output, Error **errp) { GPid pid; @@ -398,6 +408,7 @@ GuestExec *qmp_guest_exec(const char *path, GIOChannel *in_ch, *out_ch, *err_ch; GSpawnFlags flags; bool has_output = (has_capture_output && capture_output); + bool has_merge = (has_merge_output && merge_output); g_autofree uint8_t *input = NULL; size_t ninput = 0; @@ -421,7 +432,7 @@ GuestExec *qmp_guest_exec(const char *path, } ret = g_spawn_async_with_pipes(NULL, argv, envp, flags, - guest_exec_task_setup, NULL, &pid, input_data ? &in_fd : NULL, + guest_exec_task_setup, &has_merge, &pid, input_data ? &in_fd : NULL, has_output ? &out_fd : NULL, has_output ? &err_fd : NULL, &gerr); if (!ret) { error_setg(errp, QERR_QGA_COMMAND_FAILED, gerr->message); diff --git a/qga/qapi-schema.json b/qga/qapi-schema.json index 796434ed34..4192fcc5a4 100644 --- a/qga/qapi-schema.json +++ b/qga/qapi-schema.json @@ -1211,6 +1211,9 @@ # @input-data: data to be passed to process stdin (base64 encoded) # @capture-output: bool flag to enable capture of # stdout/stderr of running process. defaults to false. +# @merge-output: bool flag to merge stdout/stderr of running process +# into stdout. only effective if used with @capture-output. +# defaults to false. # # Returns: PID on success. # @@ -1218,7 +1221,8 @@ ## { 'command': 'guest-exec', 'data': { 'path': 'str', '*arg': ['str'], '*env': ['str'], - '*input-data': 'str', '*capture-output': 'bool' }, + '*input-data': 'str', '*capture-output': 'bool', + '*merge-output': 'bool' }, 'returns': 'GuestExec' } -- 2.39.1