hush: wait for `cmd` to complete, and immediately store its exitcode in $?

function                                             old     new   delta
expand_vars_to_list                                 2129    2197     +68

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

1 files changed, 18 insertions, 18 deletions

diff --git a/shell/hush.c b/shell/hush.c
index 891d87be7..6f394d1d5 100644
--- a/shell/hush.c
+++ b/shell/hush.c
@@ -2287,7 +2287,7 @@ static NOINLINE int expand_vars_to_list(o_string *output, int n, char *arg, char
                          * expanded result may need to be globbed
                          * and $IFS-splitted */
                         debug_printf_subst("SUBST '%s' first_ch %x\n", arg, first_ch);
-                        process_command_subs(&subst_result, arg);
+                        G.last_exitcode = process_command_subs(&subst_result, arg);
                         debug_printf_subst("SUBST RES '%s'\n", subst_result.data);
                         val = subst_result.data;
                         goto store_val;
@@ -3904,7 +3904,7 @@ static NOINLINE int run_pipe(struct pipe *pi)
                 /* if someone gives us an empty string: `cmd with empty output` */
                 if (!argv_expanded[0]) {
                         debug_leave();
-                        return 0;
+                        return 0; // or G.last_exitcode? see emptytick.tests
                 }
 
                 x = find_builtin(argv_expanded[0]);
@@ -5202,10 +5202,10 @@ static int fetch_heredocs(int heredoc_cnt, struct parse_context *ctx, struct in_
 
 
 #if ENABLE_HUSH_TICK
-static FILE *generate_stream_from_string(const char *s)
+static FILE *generate_stream_from_string(const char *s, pid_t *pid_p)
 {
-        FILE *pf;
-        int pid, channel[2];
+        pid_t pid;
+        int channel[2];
 # if !BB_MMU
         char **to_free;
 # endif
@@ -5291,6 +5291,7 @@ static FILE *generate_stream_from_string(const char *s)
         }
 
         /* parent */
+        *pid_p = pid;
 # if ENABLE_HUSH_FAST
         G.count_SIGCHLD++;
 //bb_error_msg("[%d] fork in generate_stream_from_string: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
@@ -5300,8 +5301,8 @@ static FILE *generate_stream_from_string(const char *s)
         free(to_free);
 # endif
         close(channel[1]);
-        pf = fdopen(channel[0], "r");
-        return pf;
+//TODO: libbb: fdopen_or_die?
+        return fdopen(channel[0], "r");
 }
 
 /* Return code is exit status of the process that is run. */
@@ -5309,9 +5310,10 @@ static int process_command_subs(o_string *dest, const char *s)
 {
         FILE *pf;
         struct in_str pipe_str;
-        int ch, eol_cnt;
+        pid_t pid;
+        int status, ch, eol_cnt;
 
-        pf = generate_stream_from_string(s);
+        pf = generate_stream_from_string(s, &pid);
         if (pf == NULL)
                 return 1;
         close_on_exec_on(fileno(pf));
@@ -5331,16 +5333,14 @@ static int process_command_subs(o_string *dest, const char *s)
                 o_addQchr(dest, ch);
         }
 
-        debug_printf("done reading from pipe, pclose()ing\n");
-        /* Note: we got EOF, and we just close the read end of the pipe.
-         * We do not wait for the `cmd` child to terminate. bash and ash do.
-         * Try these:
-         * echo `echo Hi; exec 1>&-; sleep 2` - bash waits 2 sec
-         * `false`; echo $? - bash outputs "1"
-         */
+        debug_printf("done reading from `cmd` pipe, closing it\n");
         fclose(pf);
-        debug_printf("closed FILE from child. return 0\n");
-        return 0;
+        /* We need to extract exitcode. Test case
+         * "true; echo `sleep 1; false` $?"
+         * should print 1 */
+        safe_waitpid(pid, &status, 0);
+        debug_printf("child exited. returning its exitcode:%d\n", WEXITSTATUS(status));
+        return WEXITSTATUS(status);
 }
 #endif /* ENABLE_HUSH_TICK */