The latest patch from Larry
authorEric Andersen <andersen@codepoet.org>
Mon, 21 May 2001 16:18:22 +0000 (16:18 -0000)
committerEric Andersen <andersen@codepoet.org>
Mon, 21 May 2001 16:18:22 +0000 (16:18 -0000)
hush.c
shell/hush.c

diff --git a/hush.c b/hush.c
index a1e65b24eb29218af90231628479c45313189570..fc45bb270979af01c0383ad4562af76f851dfc97 100644 (file)
--- a/hush.c
+++ b/hush.c
@@ -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;
        }
index a1e65b24eb29218af90231628479c45313189570..fc45bb270979af01c0383ad4562af76f851dfc97 100644 (file)
@@ -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;
        }