BSD 2 development

[unix-history] / .ref-BSD-1 / ex-1.1 / ex_unix.c

#
/*
* Ex - a text editor
* Bill Joy UCB September, 1977
*/

#include "ex.h"

#define UXBSZ   100

char    uxb[UXBSZ + 2];

unix()
{
       register char *up, *fp;
       register c;
       char printub, puxb[UXBSZ + 2];

       setnoaddr();
       printub = 0;
       strcpy(puxb, uxb);
       c = getchar();
       if (c == '\n' || c == EOF)
               error("Incomplete shell escape command@- use 'shell' to get a shell");
       up = uxb;
       do {
               switch (c) {
                       case '\\':
                               if (any(peekchar(), "%`!"))
                                       c = getchar();
                       default:
                               if (up >= &uxb[UXBSZ]) {
tunix:
                                       uxb[0] = 0;
                                       error("Command too long@- limit 100 characters");
                               }
                               *up++ = c;
                               break;
                       case '!':
                               fp = puxb;
                               if (*fp == 0) {
                                       uxb[0] = 0;
                                       error("No previous command@to substitute for !");
                               }
                               printub++;
                               while (*fp) {
                                       if (up >= &uxb[UXBSZ])
                                               goto tunix;
                                       *up++ = *fp++;
                               }
                               break;
                       case '`':
                               fp = altfile;
                               if (*fp == 0) {
                                       uxb[0] = 0;
                                       error("No alternate filename@to substitute for `");
                               }
                               goto uexp;
                       case '%':
                               fp = savedfile;
                               if (*fp == 0) {
                                       uxb[0] = 0;
                                       error("No filename@to substitute for %%");
                               }
uexp:
                               printub++;
                               while (*fp) {
                                       if (up >= &uxb[UXBSZ])
                                               goto tunix;
                                       *up++ = *fp++ | QUOTE;
                               }
                               break;
               }
               c = getchar();
       } while (c == '|' || !endcmd(c));
       *up = 0;
       up = uxb;
       unix2("-c", printub, uxb);
}

unix2(opt, printub, up)
       char *opt, printub, *up;
{
       register int savint;

       if (chngflag && xchngflag != chngflag) {
               xchngflag = chngflag;
               if (!value(FORK))
                       error("No write@since last change");
               dingdong();
               printf(mesg("[No write]\n|[No write since last change]\n"));
               flush();
       }
       if (value(HUSH) == 0 && printub) {
               if (uxb[0] == 0)
                       error("No previous command@to repeat");
               lprintf("!%s\n", uxb);
               flush();
       }
       savint = signal(INTR, 1);
       pid = fork();
       if (pid < 0) {
               signal(INTR, savint);
               error("No more processes");
       }
       if (pid == 0) {
/*
               if (io)
                       close(io);
               if (tfile)
                       close(tfile);
               close(erfile);
*/
               signal(HUP, oldhup);
               signal(QUIT, oldquit);
               execl(value(SHELL), "sh", opt, up, 0);
               die++;
               error("No %s!\n", value(SHELL));
       }
       waitfor();
       signal(INTR, savint);
       if (value(HUSH) == 0)
               printf("!\n");
       flush();
       termreset();
       gettmode();
}