Some cleanups for hush. Saves about 350bytes.

 -Erik

1 files changed, 67 insertions, 98 deletions

diff --git a/shell/hush.c b/shell/hush.c
index 3b1e53c82..a9d3a16ac 100644
--- a/shell/hush.c
+++ b/shell/hush.c
@@ -217,11 +217,6 @@ struct pipe {
         reserved_style r_mode;          /* supports if, for, while, until */
 };
 
-struct jobset {
-        struct pipe *head;                      /* head of list of running jobs */
-        struct pipe *fg;                        /* current foreground job */
-};
-
 struct close_me {
         int fd;
         struct close_me *next;
@@ -253,8 +248,10 @@ static int fake_mode;
 static int interactive;
 static struct close_me *close_me_head;
 static const char *cwd;
-static struct jobset *job_list;
+static struct pipe *job_list;
 static unsigned int last_bg_pid;
+static unsigned int last_jobid;
+static unsigned int ctty;
 static char *PS1;
 static char *PS2;
 struct variables shell_ver = { "HUSH_VERSION", "0.01", 1, 1, 0 };
@@ -361,10 +358,8 @@ static int free_pipe_list(struct pipe *head, int indent);
 static int free_pipe(struct pipe *pi, int indent);
 /*  really run the final data structures: */
 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);
@@ -392,7 +387,7 @@ static int parse_stream_outer(struct in_str *inp);
 static int parse_string_outer(const char *s);
 static int parse_file_outer(FILE *f);
 /*   job management: */
-static void checkjobs();
+static int checkjobs(struct pipe* fg_pipe);
 static void insert_bg_job(struct pipe *pi);
 static void remove_bg_job(struct pipe *pi);
 /*     local variable support */
@@ -543,10 +538,12 @@ static int builtin_fg_bg(struct child_prog *child)
         int i, jobnum;
         struct pipe *pi=NULL;
 
+        if (!interactive)
+                return EXIT_FAILURE;
         /* If they gave us no args, assume they want the last backgrounded task */
         if (!child->argv[1]) {
-                for (pi = job_list->head; pi; pi = pi->next) {
-                        if (pi->progs && pi->progs->pid == last_bg_pid) {
+                for (pi = job_list; pi; pi = pi->next) {
+                        if (pi->jobid == last_jobid) {
                                 break;
                         }
                 }
@@ -560,7 +557,7 @@ static int builtin_fg_bg(struct child_prog *child)
                         return EXIT_FAILURE;
                 }
 
-                for (pi = job_list->head; pi; pi = pi->next) {
+                for (pi = job_list; pi; pi = pi->next) {
                         if (pi->jobid == jobnum) {
                                 break;
                         }
@@ -574,10 +571,9 @@ static int builtin_fg_bg(struct child_prog *child)
                 /* Make this job the foreground job */
                 signal(SIGTTOU, SIG_IGN);
                 /* suppress messages when run from /linuxrc mag@sysgo.de */
-                if (tcsetpgrp(0, pi->pgrp) && errno != ENOTTY)
+                if (tcsetpgrp(ctty, pi->pgrp) && errno != ENOTTY)
                         perror_msg("tcsetpgrp-1"); 
                 signal(SIGTTOU, SIG_DFL);
-                job_list->fg = pi;
         }
 
         /* Restart the processes in the job */
@@ -612,7 +608,7 @@ static int builtin_jobs(struct child_prog *child)
         struct pipe *job;
         char *status_string;
 
-        for (job = job_list->head; job; job = job->next) {
+        for (job = job_list; job; job = job->next) {
                 if (job->running_progs == job->stopped_progs)
                         status_string = "Stopped";
                 else
@@ -1044,27 +1040,6 @@ static void restore_redirects(int squirrel[])
         }
 }
 
-/* XXX this definitely needs some more thought, work, and
- * cribbing from other shells */
-static int pipe_wait(struct pipe *pi)
-{
-        int rcode=0, i, pid, running, status;
-        running = pi->num_progs;
-        while (running) {
-                pid=waitpid(-1, &status, 0);
-                if (pid < 0) perror_msg_and_die("waitpid");
-                for (i=0; i < pi->num_progs; i++) {
-                        if (pi->progs[i].pid == pid) {
-                                if (i==pi->num_progs-1) rcode=WEXITSTATUS(status);
-                                pi->progs[i].pid = 0;
-                                running--;
-                                break;
-                        }
-                }
-        }
-        return rcode;
-}
-
 /* never returns */
 /* XXX no exit() here.  If you don't exec, use _exit instead.
  * The at_exit handlers apparently confuse the calling process,
@@ -1161,15 +1136,15 @@ static void insert_bg_job(struct pipe *pi)
 
         /* Linear search for the ID of the job to use */
         pi->jobid = 1;
-        for (thejob = job_list->head; thejob; thejob = thejob->next)
+        for (thejob = job_list; thejob; thejob = thejob->next)
                 if (thejob->jobid >= pi->jobid)
                         pi->jobid = thejob->jobid + 1;
 
         /* add thejob to the list of running jobs */
-        if (!job_list->head) {
-                thejob = job_list->head = xmalloc(sizeof(*thejob));
+        if (!job_list) {
+                thejob = job_list= xmalloc(sizeof(*thejob));
         } else {
-                for (thejob = job_list->head; thejob->next; thejob = thejob->next) /* nothing */;
+                for (thejob = job_list; thejob->next; thejob = thejob->next) /* nothing */;
                 thejob->next = xmalloc(sizeof(*thejob));
                 thejob = thejob->next;
         }
@@ -1194,17 +1169,18 @@ static void insert_bg_job(struct pipe *pi)
            to the list of backgrounded thejobs and leave it alone */
         printf("[%d] %d\n", thejob->jobid, thejob->progs[0].pid);
         last_bg_pid = thejob->progs[0].pid;
+        last_jobid = thejob->jobid;
 }
 
-/* remove a backgrounded job from a jobset */
+/* remove a backgrounded job */
 static void remove_bg_job(struct pipe *pi)
 {
         struct pipe *prev_pipe;
 
-        if (pi == job_list->head) {
-                job_list->head = pi->next;
+        if (pi == job_list) {
+                job_list= pi->next;
         } else {
-                prev_pipe = job_list->head;
+                prev_pipe = job_list;
                 while (prev_pipe->next != pi)
                         prev_pipe = prev_pipe->next;
                 prev_pipe->next = pi->next;
@@ -1214,17 +1190,35 @@ static void remove_bg_job(struct pipe *pi)
         free(pi);
 }
 
-/* Checks to see if any background processes have exited -- if they 
+/* Checks to see if any processes have exited -- if they 
    have, figure out why and see if a job has completed */
-static void checkjobs()
+static int checkjobs(struct pipe* fg_pipe)
 {
-        int status, ctty;
+        int attributes;
+        int status;
         int prognum = 0;
         struct pipe *pi;
         pid_t childpid;
 
-        while ((childpid = waitpid(-1, &status, WNOHANG | WUNTRACED)) > 0) {
-                for (pi = job_list->head; pi; pi = pi->next) {
+        attributes = WUNTRACED;
+        if (fg_pipe==NULL) {
+                attributes |= WNOHANG;
+        }
+
+        while ((childpid = waitpid(-1, &status, attributes)) > 0) {
+                if (fg_pipe) {
+                        int i, rcode = 0;
+                        for (i=0; i < fg_pipe->num_progs; i++) {
+                                if (fg_pipe->progs[i].pid == childpid) {
+                                        if (i==fg_pipe->num_progs-1)
+                                                rcode=WEXITSTATUS(status);
+                                        (fg_pipe->num_progs)--;
+                                        return(rcode);
+                                }
+                        }
+                }
+
+                for (pi = job_list; pi; pi = pi->next) {
                         prognum = 0;
                         while (prognum < pi->num_progs &&
                                    pi->progs[prognum].pid != childpid) prognum++;
@@ -1261,10 +1255,9 @@ static void checkjobs()
                 perror_msg("waitpid");
 
         /* move the shell to the foreground */
-        if (interactive && (ctty=controlling_tty(0))!=-1) {
-                if (tcsetpgrp(ctty, getpgrp()))
-                        perror_msg("tcsetpgrp-2");
-        }
+        if (interactive && tcsetpgrp(ctty, getpgid(0)))
+                perror_msg("tcsetpgrp-2");
+        return -1;
 }
 
 /* Figure out our controlling tty, checking in order stderr,
@@ -1272,24 +1265,27 @@ static void checkjobs()
  * 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)
+void 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;
+                        && (curpgrp = tcgetpgrp(ctty = 0)) < 0
+                        && (curpgrp = tcgetpgrp(ctty = 1)) < 0)
+                goto ctty_error;
+
+        if (check_pgrp && curpgrp != getpgid(0))
+                goto ctty_error;
 
-        if (check_pgrp && curpgrp != getpgrp())
-                return errno = EPERM, -1;
+        return;
 
-        return ctty;
+ctty_error:
+                ctty = -1;
+                return;
 }
 
 /* run_pipe_real() starts all the jobs, but doesn't wait for anything
- * to finish.  See pipe_wait().
+ * to finish.  See checkjobs().
  *
  * return code is normally -1, when the caller has to wait for children
  * to finish to determine the exit status of the pipe.  If the pipe
@@ -1307,21 +1303,14 @@ int controlling_tty(int check_pgrp)
 static int run_pipe_real(struct pipe *pi)
 {
         int i;
-        int ctty;
         int nextin, nextout;
         int pipefds[2];                         /* pipefds[0] is for reading */
         struct child_prog *child;
         struct built_in_command *x;
 
-        ctty = -1;
         nextin = 0;
         pi->pgrp = -1;
 
-        /* Check if we are supposed to run in the foreground */
-        if (interactive && pi->followup!=PIPE_BG) {
-                if ((ctty = controlling_tty(pi->pgrp<0)) < 0) return -1;
-        }
-
         /* Check if this is a simple builtin (not part of a pipe).
          * Builtins within pipes have to fork anyway, and are handled in
          * pseudo_exec.  "echo foo | read bar" doesn't work on bash, either.
@@ -1492,15 +1481,13 @@ 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)
+                                if (tcsetpgrp(ctty, pi->pgrp) && errno != ENOTTY)
                                         perror_msg("tcsetpgrp-3");
-                                rcode = pipe_wait(pi);
-                                if (tcsetpgrp(0, getpgrp()) && errno != ENOTTY)
+                                rcode = checkjobs(pi);
+                                if (tcsetpgrp(ctty, getpgid(0)) && errno != ENOTTY)
                                         perror_msg("tcsetpgrp-4");
                         } else {
-                                rcode = pipe_wait(pi);
+                                rcode = checkjobs(pi);
                         }
                         debug_printf("pipe_wait returned %d\n",rcode);
                 }
@@ -1511,7 +1498,7 @@ static int run_list_real(struct pipe *pi)
                      (rcode!=EXIT_SUCCESS && pi->followup==PIPE_AND) )
                         skip_more_in_this_rmode=rmode;
         }
-        checkjobs();
+        checkjobs(NULL);
         return rcode;
 }
 
@@ -2530,29 +2517,10 @@ static int parse_file_outer(FILE *f)
 }
 
 
-/* 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;
         FILE *input;
-        struct jobset joblist_end = { NULL, NULL };
         char **e = environ;
 
         /* XXX what should these be while sourcing /etc/profile? */
@@ -2568,10 +2536,11 @@ int shell_main(int argc, char **argv)
         interactive = 0;
         close_me_head = NULL;
         last_bg_pid = 0;
+        last_jobid = 0;
 
         /* Initialize some more globals to non-zero values */
         set_cwd();
-        job_list = &joblist_end;
+        job_list = NULL;
 #ifdef BB_FEATURE_COMMAND_EDITING
         cmdedit_set_initial_prompt();
 #else
@@ -2594,9 +2563,10 @@ int shell_main(int argc, char **argv)
          * don't fight over who gets the foreground */
         /* don't pay any attention to this signal; it just confuses 
            things and isn't really meant for shells anyway */
+        controlling_tty(0);
         signal(SIGTTOU, SIG_IGN);
         setpgid(0, getpid());
-        tcsetpgrp(fileno(stderr), getpid());
+        tcsetpgrp(ctty, getpid());
 
         if (argv[0] && argv[0][0] == '-') {
                 debug_printf("\nsourcing /etc/profile\n");
@@ -2650,7 +2620,6 @@ 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);