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hush: explain why "pipe; exit $?" doesn't show correct exitcode

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This commit is contained in:
Denis Vlasenko 2007-04-21 10:01:14 +00:00
parent 87cb2db703
commit 2f1bb36a55
2 changed files with 21 additions and 12 deletions
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5
shell/README
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@ -1,5 +1,10 @@
Various bits of what is known about busybox shells, in no particular order. 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 2007-04-21
hush: removed setsid() and made job control sort-of-sometimes-work. hush: removed setsid() and made job control sort-of-sometimes-work.
Ctrl-C in "rm -i" works now except for SH_STANDALONE case. Ctrl-C in "rm -i" works now except for SH_STANDALONE case.

28
shell/hush.c
View File

@ -1541,7 +1541,7 @@ static int run_pipe_real(struct pipe *pi)
pi->running_progs++; 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) if (pi->pgrp < 0)
pi->pgrp = child->pid; pi->pgrp = child->pid;
@ -1612,7 +1612,7 @@ static int run_list_real(struct pipe *pi)
skip_more_in_this_rmode = RES_XXXX; skip_more_in_this_rmode = RES_XXXX;
if (rmode == RES_THEN || rmode == RES_ELSE) if (rmode == RES_THEN || rmode == RES_ELSE)
if_code = next_if_code; if_code = next_if_code;
if (rmode == RES_THEN && if_code) if (rmode == RES_THEN && if_code)
continue; continue;
if (rmode == RES_ELSE && !if_code) if (rmode == RES_ELSE && !if_code)
continue; continue;
@ -2814,7 +2814,8 @@ static int parse_stream_outer(struct in_str *inp, int flag)
ctx.type = flag; ctx.type = flag;
initialize_context(&ctx); initialize_context(&ctx);
update_ifs_map(); 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; inp->promptmode = 1;
rcode = parse_stream(&temp, &ctx, inp, '\n'); rcode = parse_stream(&temp, &ctx, inp, '\n');
if (rcode != 1 && ctx.old_flag != 0) { 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.nonnull = 0;
temp.quote = 0; temp.quote = 0;
inp->p = NULL; inp->p = NULL;
free_pipe_list(ctx.list_head,0); free_pipe_list(ctx.list_head, 0);
} }
b_free(&temp); b_free(&temp);
} while (rcode != -1 && !(flag & FLAG_EXIT_FROM_LOOP)); /* loop on syntax errors, return on EOF */ } 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; 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); fcntl(interactive_fd, F_SETFD, FD_CLOEXEC);
/* Loop until we are in the foreground. */ /* 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); opt = parse_string_outer(optarg, FLAG_PARSE_SEMICOLON);
goto final_return; goto final_return;
case 'i': case 'i':
/*interactive_fd++;*/ //huh?? // Well, we cannot just declare interactiveness,
// we have to have some stuff (ctty, etc)
/*interactive_fd++;*/
break; break;
case 'f': case 'f':
fake_mode++; fake_mode++;
@ -2980,8 +2985,6 @@ int hush_main(int argc, char **argv)
saved_tty_pgrp = tcgetpgrp(STDIN_FILENO); saved_tty_pgrp = tcgetpgrp(STDIN_FILENO);
debug_printf("saved_tty_pgrp=%d\n", saved_tty_pgrp); debug_printf("saved_tty_pgrp=%d\n", saved_tty_pgrp);
if (saved_tty_pgrp >= 0) { 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 */ /* try to dup to high fd#, >= 255 */
interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255); interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
if (interactive_fd < 0) { if (interactive_fd < 0) {
@ -2991,17 +2994,14 @@ int hush_main(int argc, char **argv)
/* give up */ /* give up */
interactive_fd = 0; interactive_fd = 0;
} }
// TODO: track & disallow any attempts of user
// to (inadvertently) close/redirect it
} }
} }
debug_printf("\ninteractive_fd=%d\n", interactive_fd); debug_printf("\ninteractive_fd=%d\n", interactive_fd);
if (interactive_fd) { if (interactive_fd) {
/* Looks like they want an interactive shell */ /* 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(); setup_job_control();
/* Make xfuncs do cleanup on exit */ /* Make xfuncs do cleanup on exit */
die_sleep = -1; /* flag */ die_sleep = -1; /* flag */
@ -3009,6 +3009,10 @@ int hush_main(int argc, char **argv)
/* xfunc has failed! die die die */ /* xfunc has failed! die die die */
hush_exit(xfunc_error_retval); 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) { if (argv[optind] == NULL) {