2f1bb36a5
Denis Vlasenko
2007-04-21
Subject
hush: explain why "pipe; exit $?" doesn't show correct exitcode
Binary
No binary (build failed)
Architecture & Compiler Flags
—
Build Log
(log yok)
Commit Diff GitHub →
shell/README+5 -0
| @@ -1,5 +1,10 @@ | |
| Various bits of what is known about busybox shells, in no particular order. | |
| + | 2007-04-22 |
| + | hush: "sleep 1 | exit 3; echo $?" prints 0 because $? is substituted |
| + | _before_ pipe gets executed!! run_list_real() already has "pipe;echo" |
| + | parsed and handed to it for execution, so it sees "pipe"; "echo 0". |
| + | |
| 2007-04-21 | |
| hush: removed setsid() and made job control sort-of-sometimes-work. | |
| Ctrl-C in "rm -i" works now except for SH_STANDALONE case. | |
shell/hush.c+16 -12
| @@ -1541,7 +1541,7 @@ static int run_pipe_real(struct pipe *pi) | |
| pi->running_progs++; | |
| - | /* Second and next children need to know ipd of first one */ |
| + | /* Second and next children need to know pid of first one */ |
| if (pi->pgrp < 0) | |
| pi->pgrp = child->pid; | |
| @@ -1612,7 +1612,7 @@ static int run_list_real(struct pipe *pi) | |
| skip_more_in_this_rmode = RES_XXXX; | |
| if (rmode == RES_THEN || rmode == RES_ELSE) | |
| if_code = next_if_code; | |
| - | if (rmode == RES_THEN && if_code) |
| + | if (rmode == RES_THEN && if_code) |
| continue; | |
| if (rmode == RES_ELSE && !if_code) | |
| continue; | |
| @@ -2814,7 +2814,8 @@ static int parse_stream_outer(struct in_str *inp, int flag) | |
| ctx.type = flag; | |
| initialize_context(&ctx); | |
| update_ifs_map(); | |
| - | if (!(flag & FLAG_PARSE_SEMICOLON) || (flag & FLAG_REPARSING)) mapset(";$&|", 0); |
| + | if (!(flag & FLAG_PARSE_SEMICOLON) || (flag & FLAG_REPARSING)) |
| + | mapset(";$&|", 0); |
| inp->promptmode = 1; | |
| rcode = parse_stream(&temp, &ctx, inp, '\n'); | |
| if (rcode != 1 && ctx.old_flag != 0) { | |
| @@ -2832,7 +2833,7 @@ static int parse_stream_outer(struct in_str *inp, int flag) | |
| temp.nonnull = 0; | |
| temp.quote = 0; | |
| inp->p = NULL; | |
| - | free_pipe_list(ctx.list_head,0); |
| + | free_pipe_list(ctx.list_head, 0); |
| } | |
| b_free(&temp); | |
| } while (rcode != -1 && !(flag & FLAG_EXIT_FROM_LOOP)); /* loop on syntax errors, return on EOF */ | |
| @@ -2862,6 +2863,8 @@ static void setup_job_control(void) | |
| { | |
| pid_t shell_pgrp; | |
| + | saved_task_pgrp = getpgrp(); |
| + | debug_printf("saved_task_pgrp=%d\n", saved_task_pgrp); |
| fcntl(interactive_fd, F_SETFD, FD_CLOEXEC); | |
| /* Loop until we are in the foreground. */ | |
| @@ -2952,7 +2955,9 @@ int hush_main(int argc, char **argv) | |
| opt = parse_string_outer(optarg, FLAG_PARSE_SEMICOLON); | |
| goto final_return; | |
| case 'i': | |
| - | /*interactive_fd++;*/ //huh?? |
| + | // Well, we cannot just declare interactiveness, |
| + | // we have to have some stuff (ctty, etc) |
| + | /*interactive_fd++;*/ |
| break; | |
| case 'f': | |
| fake_mode++; | |
| @@ -2980,8 +2985,6 @@ int hush_main(int argc, char **argv) | |
| saved_tty_pgrp = tcgetpgrp(STDIN_FILENO); | |
| debug_printf("saved_tty_pgrp=%d\n", saved_tty_pgrp); | |
| if (saved_tty_pgrp >= 0) { | |
| - | saved_task_pgrp = getpgrp(); |
| - | debug_printf("saved_task_pgrp=%d\n", saved_task_pgrp); |
| /* try to dup to high fd#, >= 255 */ | |
| interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255); | |
| if (interactive_fd < 0) { | |
| @@ -2991,17 +2994,14 @@ int hush_main(int argc, char **argv) | |
| /* give up */ | |
| interactive_fd = 0; | |
| } | |
| + | // TODO: track & disallow any attempts of user |
| + | // to (inadvertently) close/redirect it |
| } | |
| } | |
| debug_printf("\ninteractive_fd=%d\n", interactive_fd); | |
| if (interactive_fd) { | |
| /* Looks like they want an interactive shell */ | |
| - | #if !ENABLE_FEATURE_SH_EXTRA_QUIET |
| - | printf( "\n\n%s hush - the humble shell v0.01 (testing)\n", |
| - | BB_BANNER); |
| - | printf( "Enter 'help' for a list of built-in commands.\n\n"); |
| - | #endif |
| setup_job_control(); | |
| /* Make xfuncs do cleanup on exit */ | |
| die_sleep = -1; /* flag */ | |
| @@ -3009,6 +3009,10 @@ int hush_main(int argc, char **argv) | |
| /* xfunc has failed! die die die */ | |
| hush_exit(xfunc_error_retval); | |
| } | |
| + | #if !ENABLE_FEATURE_SH_EXTRA_QUIET |
| + | printf("\n\n%s hush - the humble shell v0.02\n", BB_BANNER); |
| + | printf("Enter 'help' for a list of built-in commands.\n\n"); |
| + | #endif |
| } | |
| if (argv[optind] == NULL) { | |