52881e9f2
Denis Vlasenko
2007-04-21
Subject
hush: fix more backgrounding bugs. Plenty of them remains still.
Binary
No binary (build failed)
Architecture & Compiler Flags
—
Build Log
(log yok)
Commit Diff GitHub →
shell/README+7 -1
| @@ -1,6 +1,12 @@ | |
| Various bits of what is known about busybox shells, in no particular order. | |
| - | 2007-04-22 |
| + | 2007-04-21 |
| + | hush: fixed non-backgrounding of "sleep 1 &" and totally broken |
| + | "sleep 1 | sleep 2 &". Noticed a bug where successive jobs |
| + | get numbers 1,2,3 even when job #1 has exited before job# 2 is started. |
| + | (bash reuses #1 in this case) |
| + | |
| + | 2007-04-21 |
| 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". | |
shell/hush.c+22 -10
| @@ -384,6 +384,7 @@ static int parse_string_outer(const char *s, int flag); | |
| static int parse_file_outer(FILE *f); | |
| /* job management: */ | |
| static int checkjobs(struct pipe* fg_pipe); | |
| + | static int checkjobs_and_fg_shell(struct pipe* fg_pipe); |
| static void insert_bg_job(struct pipe *pi); | |
| static void remove_bg_job(struct pipe *pi); | |
| /* local variable support */ | |
| @@ -648,6 +649,8 @@ static int builtin_fg_bg(struct child_prog *child) | |
| bb_error_msg("%s: %d: no such job", child->argv[0], jobnum); | |
| return EXIT_FAILURE; | |
| found: | |
| + | // TODO: bash prints a string representation |
| + | // of job being foregrounded (like "sleep 1 | cat") |
| if (*child->argv[0] == 'f') { | |
| /* Put the job into the foreground. */ | |
| tcsetpgrp(interactive_fd, pi->pgrp); | |
| @@ -658,6 +661,7 @@ static int builtin_fg_bg(struct child_prog *child) | |
| pi->progs[i].is_stopped = 0; | |
| i = kill(- pi->pgrp, SIGCONT); | |
| + | pi->stopped_progs = 0; |
| if (i < 0) { | |
| if (errno == ESRCH) { | |
| remove_bg_job(pi); | |
| @@ -666,7 +670,8 @@ static int builtin_fg_bg(struct child_prog *child) | |
| } | |
| } | |
| - | pi->stopped_progs = 0; |
| + | if (*child->argv[0] == 'f') |
| + | return checkjobs_and_fg_shell(pi); |
| return EXIT_SUCCESS; | |
| } | |
| @@ -1350,6 +1355,18 @@ static int checkjobs(struct pipe* fg_pipe) | |
| return rcode; | |
| } | |
| + | static int checkjobs_and_fg_shell(struct pipe* fg_pipe) |
| + | { |
| + | pid_t p; |
| + | int rcode = checkjobs(fg_pipe); |
| + | /* Job finished, move the shell to the foreground */ |
| + | p = getpgid(0); |
| + | debug_printf("fg'ing ourself: getpgid(0)=%d\n", (int)p); |
| + | if (tcsetpgrp(interactive_fd, p) && errno != ENOTTY) |
| + | bb_perror_msg("tcsetpgrp-4a"); |
| + | return rcode; |
| + | } |
| + | |
| /* run_pipe_real() starts all the jobs, but doesn't wait for anything | |
| * to finish. See checkjobs(). | |
| * | |
| @@ -1377,6 +1394,7 @@ static int run_pipe_real(struct pipe *pi) | |
| /* it is not always needed, but we aim to smaller code */ | |
| int squirrel[] = { -1, -1, -1 }; | |
| int rcode; | |
| + | const int single_fg = (pi->num_progs == 1 && pi->followup != PIPE_BG); |
| nextin = 0; | |
| pi->pgrp = -1; | |
| @@ -1386,7 +1404,7 @@ static int run_pipe_real(struct pipe *pi) | |
| * pseudo_exec. "echo foo | read bar" doesn't work on bash, either. | |
| */ | |
| child = &(pi->progs[0]); | |
| - | if (pi->num_progs == 1 && child->group && child->subshell == 0) { |
| + | if (single_fg && child->group && child->subshell == 0) { |
| debug_printf("non-subshell grouping\n"); | |
| setup_redirects(child, squirrel); | |
| /* XXX could we merge code with following builtin case, | |
| @@ -1396,7 +1414,7 @@ static int run_pipe_real(struct pipe *pi) | |
| return rcode; | |
| } | |
| - | if (pi->num_progs == 1 && pi->progs[0].argv != NULL) { |
| + | if (single_fg && pi->progs[0].argv != NULL) { |
| for (i = 0; is_assignment(child->argv[i]); i++) | |
| continue; | |
| if (i != 0 && child->argv[i] == NULL) { | |
| @@ -1675,13 +1693,7 @@ static int run_list_real(struct pipe *pi) | |
| rcode = EXIT_SUCCESS; | |
| } else { | |
| if (interactive_fd) { | |
| - | pid_t p; |
| - | rcode = checkjobs(pi); |
| - | /* move the shell to the foreground */ |
| - | p = getpgid(0); |
| - | if (tcsetpgrp(interactive_fd, p) && errno != ENOTTY) |
| - | bb_perror_msg("tcsetpgrp-4"); |
| - | debug_printf("getpgid(0)=%d\n", (int)p); |
| + | rcode = checkjobs_and_fg_shell(pi); |
| } else { | |
| rcode = checkjobs(pi); | |
| } | |