From dbd14c4a42454b61a5474f6243865a6ec113e60b Mon Sep 17 00:00:00 2001 From: Ron Yorston Date: Tue, 9 Apr 2024 09:51:48 +0100 Subject: libbb: send usage messages to correct stream POSIX generally requires normal output to go to stdout and diagnostic (i.e. error) output to go to stderr. When usage messages for BusyBox applets are specifically requested by the user (e.g. 'find --help') they should go to stdout; when they're emitted due to an error they should go to stderr. function old new delta bb_show_usage 148 146 -2 ------------------------------------------------------------------------------ (add/remove: 0/0 grow/shrink: 0/1 up/down: 0/-2) Total: -2 bytes Signed-off-by: Avi Halachmi Signed-off-by: Ron Yorston Signed-off-by: Denys Vlasenko --- libbb/appletlib.c | 30 +++++++++++++++++------------- 1 file changed, 17 insertions(+), 13 deletions(-) diff --git a/libbb/appletlib.c b/libbb/appletlib.c index ad373ae1c..d2e5900b5 100644 --- a/libbb/appletlib.c +++ b/libbb/appletlib.c @@ -127,17 +127,19 @@ static const char packed_usage[] ALIGN1 = { PACKED_USAGE }; void FAST_FUNC bb_show_usage(void) { if (ENABLE_SHOW_USAGE) { + ssize_t FAST_FUNC (*full_write_fn)(const char *) = + xfunc_error_retval ? full_write2_str : full_write1_str; #ifdef SINGLE_APPLET_STR /* Imagine that this applet is "true". Dont link in printf! */ const char *usage_string = unpack_usage_messages(); if (usage_string) { if (*usage_string == '\b') { - full_write2_str("No help available\n"); + full_write_fn("No help available\n"); } else { - full_write2_str("Usage: "SINGLE_APPLET_STR" "); - full_write2_str(usage_string); - full_write2_str("\n"); + full_write_fn("Usage: "SINGLE_APPLET_STR" "); + full_write_fn(usage_string); + full_write_fn("\n"); } if (ENABLE_FEATURE_CLEAN_UP) dealloc_usage_messages((char*)usage_string); @@ -153,19 +155,19 @@ void FAST_FUNC bb_show_usage(void) while (*p++) continue; ap--; } - full_write2_str(bb_banner); - full_write2_str(" multi-call binary.\n"); /* common string */ + full_write_fn(bb_banner); + full_write_fn(" multi-call binary.\n"); /* common string */ if (*p == '\b') - full_write2_str("\nNo help available\n"); + full_write_fn("\nNo help available\n"); else { - full_write2_str("\nUsage: "); - full_write2_str(applet_name); + full_write_fn("\nUsage: "); + full_write_fn(applet_name); if (p[0]) { if (p[0] != '\n') - full_write2_str(" "); - full_write2_str(p); + full_write_fn(" "); + full_write_fn(p); } - full_write2_str("\n"); + full_write_fn("\n"); } if (ENABLE_FEATURE_CLEAN_UP) dealloc_usage_messages((char*)usage_string); @@ -268,8 +270,10 @@ void lbb_prepare(const char *applet && !(ENABLE_TRUE && strcmp(applet_name, "true") == 0) && !(ENABLE_FALSE && strcmp(applet_name, "false") == 0) && !(ENABLE_ECHO && strcmp(applet_name, "echo") == 0) - ) + ) { + xfunc_error_retval = 0; bb_show_usage(); + } } #endif } -- cgit v1.2.3-55-g6feb