diff options
Diffstat (limited to 'hush.c')
| -rw-r--r-- | hush.c | 92 |
1 files changed, 61 insertions, 31 deletions
@@ -365,6 +365,7 @@ static int setup_redirects(struct child_prog *prog, int squirrel[]); static int pipe_wait(struct pipe *pi); static int run_list_real(struct pipe *pi); static void pseudo_exec(struct child_prog *child) __attribute__ ((noreturn)); +int controlling_tty(int check_pgrp); static int run_pipe_real(struct pipe *pi); /* extended glob support: */ static int globhack(const char *src, int flags, glob_t *pglob); @@ -576,7 +577,7 @@ static int builtin_fg_bg(struct child_prog *child) signal(SIGTTOU, SIG_IGN); /* suppress messages when run from /linuxrc mag@sysgo.de */ if (tcsetpgrp(0, pi->pgrp) && errno != ENOTTY) - perror_msg("tcsetpgrp"); + perror_msg("tcsetpgrp-1"); signal(SIGTTOU, SIG_DFL); job_list->fg = pi; } @@ -1059,13 +1060,14 @@ static int pipe_wait(struct pipe *pi) return rcode; } -/* very simple version for testing */ +/* never returns */ static void pseudo_exec(struct child_prog *child) { int i, rcode; struct built_in_command *x; if (child->argv) { for (i=0; is_assignment(child->argv[i]); i++) { + debug_printf("pid %d environment modification: %s\n",getpid(),child->argv[i]); putenv(strdup(child->argv[i])); } child->argv+=i; /* XXX this hack isn't so horrible, since we are about @@ -1125,7 +1127,7 @@ static void pseudo_exec(struct child_prog *child) #endif debug_printf("exec of %s\n",child->argv[0]); execvp(child->argv[0],child->argv); - perror("execvp"); + perror_msg("couldn't exec: %s",child->argv[0]); exit(1); } else if (child->group) { debug_printf("runtime nesting to group\n"); @@ -1224,7 +1226,7 @@ static void free_pipe(struct pipe *pi) have, figure out why and see if a job has completed */ static void checkjobs() { - int status; + int status, ctty; int prognum = 0; struct pipe *pi; pid_t childpid; @@ -1264,8 +1266,31 @@ static void checkjobs() perror_msg("waitpid"); /* move the shell to the foreground */ - if (tcsetpgrp(0, getpgrp()) && errno != ENOTTY) - perror_msg("tcsetpgrp"); + if (interactive && (ctty=controlling_tty(0))!=-1) { + if (tcsetpgrp(ctty, getpgrp())) + perror_msg("tcsetpgrp-2"); + } +} + +/* Figure out our controlling tty, checking in order stderr, + * stdin, and stdout. If check_pgrp is set, also check that + * we belong to the foreground process group associated with + * that tty. The value of ctty is needed in order to call + * tcsetpgrp(ctty, ...); */ +int controlling_tty(int check_pgrp) +{ + pid_t curpgrp; + int ctty; + + if ((curpgrp = tcgetpgrp(ctty = 2)) < 0 + && (curpgrp = tcgetpgrp(ctty = 0)) < 0 + && (curpgrp = tcgetpgrp(ctty = 1)) < 0) + return errno = ENOTTY, -1; + + if (check_pgrp && curpgrp != getpgrp()) + return errno = EPERM, -1; + + return ctty; } /* run_pipe_real() starts all the jobs, but doesn't wait for anything @@ -1295,17 +1320,11 @@ static int run_pipe_real(struct pipe *pi) ctty = -1; nextin = 0; - pi->pgrp = 0; + pi->pgrp = -1; /* Check if we are supposed to run in the foreground */ if (interactive && pi->followup!=PIPE_BG) { - if ((pi->pgrp = tcgetpgrp(ctty = 2)) < 0 - && (pi->pgrp = tcgetpgrp(ctty = 0)) < 0 - && (pi->pgrp = tcgetpgrp(ctty = 1)) < 0) - return errno = ENOTTY, -1; - - if (pi->pgrp < 0 && pi->pgrp != getpgrp()) - return errno = EPERM, -1; + if ((ctty = controlling_tty(pi->pgrp<0)) < 0) return -1; } /* Check if this is a simple builtin (not part of a pipe). @@ -1395,11 +1414,11 @@ static int run_pipe_real(struct pipe *pi) * and the pipe fd is available for dup'ing. */ setup_redirects(child,NULL); - if (pi->followup!=PIPE_BG) { + if (interactive && pi->followup!=PIPE_BG) { /* If we (the child) win the race, put ourselves in the process * group whose leader is the first process in this pipe. */ if (pi->pgrp < 0) { - pi->pgrp = child->pid; + pi->pgrp = getpid(); } if (setpgid(0, pi->pgrp) == 0) { signal(SIGTTOU, SIG_IGN); @@ -1461,13 +1480,15 @@ static int run_list_real(struct pipe *pi) if (interactive) { /* move the new process group into the foreground */ /* suppress messages when run from /linuxrc mag@sysgo.de */ + /* XXX probably this "0" should come from controlling_tty() */ if (tcsetpgrp(0, pi->pgrp) && errno != ENOTTY) - perror_msg("tcsetpgrp"); + perror_msg("tcsetpgrp-3"); rcode = pipe_wait(pi); if (tcsetpgrp(0, getpgrp()) && errno != ENOTTY) - perror_msg("tcsetpgrp"); + perror_msg("tcsetpgrp-4"); } else { rcode = pipe_wait(pi); + debug_printf("pipe_wait returned %d\n",rcode); } } last_return_code=rcode; @@ -2484,6 +2505,25 @@ static int parse_file_outer(FILE *f) return rcode; } + +/* I think Erik wrote this. It looks imperfect at best */ +void grab_tty_control(void) +{ + pid_t initialpgrp; + do { + initialpgrp = tcgetpgrp(fileno(stderr)); + if (initialpgrp < 0) { + error_msg("sh: can't access tty; job control disabled\n"); + } + if (initialpgrp == -1) + initialpgrp = getpgrp(); + else if (initialpgrp != getpgrp()) { + killpg(initialpgrp, SIGTTIN); + continue; + } + } while (0); +} + int shell_main(int argc, char **argv) { int opt; @@ -2507,19 +2547,6 @@ int shell_main(int argc, char **argv) /* If we get started under a job aware app (like bash * for example), make sure we are now in charge so we * don't fight over who gets the foreground */ - do { - pid_t initialpgrp; - initialpgrp = tcgetpgrp(fileno(stderr)); - if (initialpgrp < 0) { - error_msg_and_die("sh: can't access tty; job control disabled\n"); - } - if (initialpgrp == -1) - initialpgrp = getpgrp(); - else if (initialpgrp != getpgrp()) { - killpg(initialpgrp, SIGTTIN); - continue; - } - } while (0); /* don't pay any attention to this signal; it just confuses things and isn't really meant for shells anyway */ signal(SIGTTOU, SIG_IGN); @@ -2588,6 +2615,9 @@ int shell_main(int argc, char **argv) if (interactive) { /* Looks like they want an interactive shell */ fprintf(stdout, "\nhush -- the humble shell v0.01 (testing)\n\n"); + grab_tty_control(); + } + if (argv[optind]==NULL) { opt=parse_file_outer(stdin); goto final_return; } |