hush: fix "trap -- handler SIGs..."; escape handlers in "trap" output

1 files changed, 117 insertions, 93 deletions

diff --git a/shell/hush.c b/shell/hush.c
index 0f93ae62b..6e181ce99 100644
--- a/shell/hush.c
+++ b/shell/hush.c
@@ -3246,14 +3246,16 @@ static int checkjobs(struct pipe* fg_pipe)
                                         fg_pipe->alive_cmds--;
                                         if (i == fg_pipe->num_cmds - 1) {
                                                 /* last process gives overall exitstatus */
+                                                /* Note: is WIFSIGNALED, WEXITSTATUS = sig + 128 */
                                                 rcode = WEXITSTATUS(status);
                                                 IF_HAS_KEYWORDS(if (fg_pipe->pi_inverted) rcode = !rcode;)
                                                 /* bash prints killing signal's name for *last*
                                                  * process in pipe (prints just newline for SIGINT).
-                                                 * we just print newline for any sig:
+                                                 * Mimic this. Example: "sleep 5" + ^\
                                                  */
                                                 if (WIFSIGNALED(status)) {
-                                                        bb_putchar('\n');
+                                                        int sig = WTERMSIG(status);
+                                                        printf("%s\n", sig == SIGINT ? "" : get_signame(sig));
                                                 }
                                         }
                                 } else {
@@ -3489,6 +3491,7 @@ static int run_pipe(struct pipe *pi)
                                         debug_printf_exec(": builtin '%s' '%s'...\n",
                                                 x->cmd, argv_expanded[1]);
                                         rcode = x->function(argv_expanded) & 0xff;
+                                        fflush(NULL);
                                 }
 #if ENABLE_HUSH_FUNCTIONS
                                 else {
@@ -6251,81 +6254,6 @@ int lash_main(int argc, char **argv)
 /*
  * Built-ins
  */
-static int builtin_trap(char **argv)
-{
-        int i;
-        int sig;
-        char *new_cmd;
-
-        if (!G.traps)
-                G.traps = xzalloc(sizeof(G.traps[0]) * NSIG);
-
-        argv++;
-        if (!*argv) {
-                /* No args: print all trapped. This isn't 100% correct as we
-                 * should be escaping the cmd so that it can be pasted back in
-                 */
-                for (i = 0; i < NSIG; ++i)
-                        if (G.traps[i])
-                                printf("trap -- '%s' %s\n", G.traps[i], get_signame(i));
-                return EXIT_SUCCESS;
-        }
-
-        new_cmd = NULL;
-        i = 0;
-        /* If first arg is decimal: reset all specified signals */
-        sig = bb_strtou(*argv, NULL, 10);
-        if (errno == 0) {
-                int ret;
- set_all:
-                ret = EXIT_SUCCESS;
-                while (*argv) {
-                        sig = get_signum(*argv++);
-                        if (sig < 0 || sig >= NSIG) {
-                                ret = EXIT_FAILURE;
-                                /* Mimic bash message exactly */
-                                bb_perror_msg("trap: %s: invalid signal specification", argv[i]);
-                                continue;
-                        }
-
-                        free(G.traps[sig]);
-                        G.traps[sig] = xstrdup(new_cmd);
-
-                        debug_printf("trap: setting SIG%s (%i) to '%s'",
-                                get_signame(sig), sig, G.traps[sig]);
-
-                        /* There is no signal for 0 (EXIT) */
-                        if (sig == 0)
-                                continue;
-
-                        if (new_cmd) {
-                                sigaddset(&G.blocked_set, sig);
-                        } else {
-                                /* There was a trap handler, we are removing it
-                                 * (if sig has non-DFL handling,
-                                 * we don't need to do anything) */
-                                if (sig < 32 && (G.non_DFL_mask & (1 << sig)))
-                                        continue;
-                                sigdelset(&G.blocked_set, sig);
-                        }
-                        sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
-                }
-                return ret;
-        }
-
-        /* First arg is "-": reset all specified to default */
-        /* First arg is "": ignore all specified */
-        /* Everything else: execute first arg upon signal */
-        if (!argv[1]) {
-                bb_error_msg("trap: invalid arguments");
-                return EXIT_FAILURE;
-        }
-        if (NOT_LONE_DASH(*argv))
-                new_cmd = *argv;
-        argv++;
-        goto set_all;
-}
-
 static int builtin_true(char **argv UNUSED_PARAM)
 {
         return 0;
@@ -6427,6 +6355,26 @@ static int builtin_exit(char **argv)
         hush_exit(xatoi(*argv) & 0xff);
 }
 
+static void print_escaped(const char *s)
+{
+        do {
+                if (*s != '\'') {
+                        const char *p;
+
+                        p = strchrnul(s, '\'');
+                        /* print 'xxxx', possibly just '' */
+                        printf("'%.*s'", (int)(p - s), s);
+                        if (*p == '\0')
+                                break;
+                        s = p;
+                }
+                /* s points to '; print "'''...'''" */
+                putchar('"');
+                do putchar('\''); while (*++s == '\'');
+                putchar('"');
+        } while (*s);
+}
+
 static int builtin_export(char **argv)
 {
         if (*++argv == NULL) {
@@ -6446,25 +6394,11 @@ static int builtin_export(char **argv)
                                         continue;
                                 /* export var= */
                                 printf("export %.*s", (int)(p - s) + 1, s);
-                                s = p + 1;
-                                while (*s) {
-                                        if (*s != '\'') {
-                                                p = strchrnul(s, '\'');
-                                                /* print 'xxxx' */
-                                                printf("'%.*s'", (int)(p - s), s);
-                                                if (*p == '\0')
-                                                        break;
-                                                s = p;
-                                        }
-                                        /* s points to '; print ''...'''" */
-                                        putchar('"');
-                                        do putchar('\''); while (*++s == '\'');
-                                        putchar('"');
-                                }
+                                print_escaped(p + 1);
                                 putchar('\n');
 #endif
                         }
-                        fflush(stdout);
+                        /*fflush(stdout); - done after each builtin anyway */
                 }
                 return EXIT_SUCCESS;
         }
@@ -6494,6 +6428,96 @@ static int builtin_export(char **argv)
         return EXIT_SUCCESS;
 }
 
+static int builtin_trap(char **argv)
+{
+        int i;
+        int sig;
+        char *new_cmd;
+
+        if (!G.traps)
+                G.traps = xzalloc(sizeof(G.traps[0]) * NSIG);
+
+        argv++;
+        if (!*argv) {
+                /* No args: print all trapped */
+                for (i = 0; i < NSIG; ++i) {
+                        if (G.traps[i]) {
+                                printf("trap -- ");
+                                print_escaped(G.traps[i]);
+                                printf(" %s\n", get_signame(i));
+                        }
+                }
+                /*fflush(stdout); - done after each builtin anyway */
+                return EXIT_SUCCESS;
+        }
+
+        new_cmd = NULL;
+        i = 0;
+        /* If first arg is a number: reset all specified signals */
+        sig = bb_strtou(*argv, NULL, 10);
+        if (errno == 0) {
+                int ret;
+ process_sig_list:
+                ret = EXIT_SUCCESS;
+                while (*argv) {
+                        sig = get_signum(*argv++);
+                        if (sig < 0 || sig >= NSIG) {
+                                ret = EXIT_FAILURE;
+                                /* Mimic bash message exactly */
+                                bb_perror_msg("trap: %s: invalid signal specification", argv[i]);
+                                continue;
+                        }
+
+                        free(G.traps[sig]);
+                        G.traps[sig] = xstrdup(new_cmd);
+
+                        debug_printf("trap: setting SIG%s (%i) to '%s'",
+                                get_signame(sig), sig, G.traps[sig]);
+
+                        /* There is no signal for 0 (EXIT) */
+                        if (sig == 0)
+                                continue;
+
+                        if (new_cmd) {
+                                sigaddset(&G.blocked_set, sig);
+                        } else {
+                                /* There was a trap handler, we are removing it
+                                 * (if sig has non-DFL handling,
+                                 * we don't need to do anything) */
+                                if (sig < 32 && (G.non_DFL_mask & (1 << sig)))
+                                        continue;
+                                sigdelset(&G.blocked_set, sig);
+                        }
+                        sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
+                }
+                return ret;
+        }
+
+        if (!argv[1]) { /* no second arg */
+                bb_error_msg("trap: invalid arguments");
+                return EXIT_FAILURE;
+        }
+
+        /* First arg is "-": reset all specified to default */
+        /* First arg is "--": skip it, the rest is "handler SIGs..." */
+        /* Everything else: set arg as signal handler
+         * (includes "" case, which ignores signal) */
+        if (argv[0][0] == '-') {
+                if (argv[0][1] == '\0') { /* "-" */
+                        /* new_cmd remains NULL: "reset these sigs" */
+                        goto reset_traps;
+                }
+                if (argv[0][1] == '-' && argv[0][2] == '\0') { /* "--" */
+                        argv++;
+                }
+                /* else: "-something", no special meaning */
+        }
+        new_cmd = *argv;
+ reset_traps:
+        argv++;
+        goto process_sig_list;
+}
+
 #if ENABLE_HUSH_JOB
 /* built-in 'fg' and 'bg' handler */
 static int builtin_fg_bg(char **argv)