The latest patch from Larry

2 files changed, 122 insertions, 62 deletions

diff --git a/hush.c b/hush.c
index a1e65b24e..fc45bb270 100644
--- 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;
         }
diff --git a/shell/hush.c b/shell/hush.c
index a1e65b24e..fc45bb270 100644
--- a/shell/hush.c
+++ b/shell/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;
         }