BSD 2 development

[unix-history] / src / dribble.c

/* Copyright (c) 1979 Regents of the University of California */
#include <signal.h>
#include <errno.h>

#define BUFSIZ  512

int     inpipe[2], outpipe[2];

int     dribfil;
int     inpid, outpid, cmdpid;
int     badpipe();
char    *nargv[3] = { "/bin/csh", "-i", 0 };

main(argc, argv)
       char *argv[];
{
       int status;

       argc--, argv++;
       if (argc < 0)
               error("Usage: dribble [ dribble.out [ command ] ] ...");
       if (pipe(outpipe) < 0) {
piperr:
               perror("pipe");
               exit(1);
       }
       dribfil = creat(argc == 0 ? "dribble.out" : argv[0], 0644);
       if (dribfil < 0) {
               perror(argc == 0 ? "dribble.out" : argv[0]);
               exit(1);
       }
       if (argc <= 1) {
               argv = nargv - 1;
               argc = 3;
               if (getenv("SHELL"))
                       argv[1] = getenv("SHELL");
               else
                       argv[1] = "/bin/sh";
       }
       inpid = getpid();
       outpid = fork();
       if (outpid < 0)
               error("No more processes");
       if (outpid == 0) {
               signal(SIGINT, SIG_IGN);
               close(0);
               close(2);
               close(outpipe[1]);
               outloop();
               /* no return */
       }
       signal(SIGTRAP, SIG_IGN);
       if (pipe(inpipe) < 0)
               goto piperr;
       cmdpid = fork();
       if (cmdpid < 0) {
               kill(outpid, SIGKILL);
               error("No more processes");
       }
       if (cmdpid == 0) {
               close(0);
               dup(inpipe[0]);
               close(1);
               dup(outpipe[1]);
               close(inpipe[0]);
               close(inpipe[1]);
               close(outpipe[0]);
               close(outpipe[1]);
               close(2);
               dup(1);
               argv[argc] = 0;
               argv++;
               doexec(argv[0], &argv[0]);
               /* no return */
       }
       signal(SIGPIPE, badpipe);
       close(inpipe[0]);
       close(outpipe[0]);
       input();
}

outloop()
{
       int cnt;
       char linebuf[BUFSIZ];
       int bufcnt;
       extern int errno;

       bufcnt = 0;
       for (;;) {
               errno = 0;
               bufcnt = read(outpipe[0], linebuf, BUFSIZ);
               if (bufcnt == 0)
                       break;
               if (bufcnt > 0) {
                       linebuf[bufcnt] = 0;
                       write(dribfil, linebuf, bufcnt);
                       write(1, linebuf, bufcnt);
               }
       }
       kill(inpid, SIGPIPE);
       exit(0);
}

input()
{
       register int i;
       char linebuf[BUFSIZ];
       int bufcnt;

       signal(SIGINT, SIG_IGN);
       for (;;) {
               do {
                       bufcnt = read(0, linebuf, BUFSIZ);
                       if (bufcnt == 0) {
                               linebuf[0] = 4;
                               linebuf[1] = '\n';
                               linebuf[2] = 0;
                               write(inpipe[1], linebuf, 3);
                               continue;
                       }
                       if (bufcnt == 3 && linebuf[0] == 'E' &&
                           linebuf[1] == 'O' && linebuf[2] == 'F') {
                               bufcnt = 4;
                               linebuf[3] = '\n';
                               write(1, "\n", 1);
                               write(dribfil, linebuf, bufcnt);
                               bufcnt = 0;
                               break;
                       }
                       if (bufcnt > 0) {
                               write(dribfil, linebuf, bufcnt);
                               write(inpipe[1], linebuf, bufcnt);
                       }
               } while (bufcnt > 0);
               if (bufcnt == 0) {
                       int status;

                       close(inpipe[1]);
                       do
                               i = wait(&status);
                       while (i > 0 && i != cmdpid);
                       exit(1);
               }
       }
}

error(cp, a1, a2, a3, a4)
       char *cp;
{

       close(1);
       open("/dev/tty", 1);
       printf(cp, a1, a2, a3, a4);
       putchar('\n');
       exit(1);
}

badpipe()
{

       kill(cmdpid, SIGKILL);
       kill(outpid, SIGKILL);
       exit(1);
}

doexec(cmd, args)
       char *cmd;
       char *args[];
{
       char cmdbuf[120];

       strcpy(cmdbuf, "");
       strcat(cmdbuf, cmd);
       execv(cmdbuf, args);
       strcpy(cmdbuf, "/usr/new/");
       strcat(cmdbuf, cmd);
       execv(cmdbuf, args);
       strcpy(cmdbuf, "/bin/");
       strcat(cmdbuf, cmd);
       execv(cmdbuf, args);
       strcpy(cmdbuf, "/usr/bin/");
       strcat(cmdbuf, cmd);
       execv(cmdbuf, args);
       error("%s: Cannot find", cmd);
}