BSD 3 development

[unix-history] / .ref-BSD-2 / src / Mail / lex.c

/* Copyright (c) 1979 Regents of the University of California */
#

#include "rcv.h"

/*
* Mail -- a mail program
*
* Lexical processing of commands.
*/

/*
* Interpret user commands one by one.  If standard input is not a tty,
* print no prompt.
*/

commands()
{
       int *msgvec, prompt, firstsw, stop(), e;
       char linebuf[LINESIZE], word[LINESIZE];
       char *arglist[MAXARGC];
       struct cmd *com, *quitp;
       register char *cp, *cp2;
       register int c;

       msgvec = (int *) calloc((unsigned) (msgCount + 1), sizeof *msgvec);
       if (rcvmode)
               if (signal(SIGINT, SIG_IGN) == SIG_DFL)
                       signal(SIGINT, stop);
       input = stdin;
       prompt = 1;
       if (!intty)
               prompt = 0;
       firstsw = 1;
       quitp = lex("quit");
       if (quitp == NONE)
               panic("No quit command!?!");
       for (;;) {
               setexit();
               if (firstsw > 0) {
                       firstsw = 0;
                       source1(mailrc);
                       source1(MASTER);
               }

               /*
                * How's this for obscure:  after we
                * finish sourcing for the first time,
                * go off and print the headers!
                */

               if (firstsw == 0 && !sourcing) {
                       firstsw = -1;
                       if (rcvmode)
                               announce();
               }

               /*
                * Print the prompt, if needed.  Clear out
                * string space, and flush the output.
                */

               if (!rcvmode && !sourcing)
                       return;
               if (prompt && !sourcing)
                       printf("_\r");
               flush();
               sreset();

               /*
                * Read a line of commands from the current input
                * and handle end of file specially.
                */

               if (readline(input, linebuf) <= 0) {
                       if (sourcing) {
                               unstack();
                               continue;
                       }
                       if (!edit) {
                               signal(SIGINT, SIG_IGN);
                               return;
                       }
                       edstop();
                       return;
               }

               /*
                * Strip the white space away from the beginning
                * of the command, then scan out a word, which
                * consists of anything except digits and white space.
                *
                * Handle ! escapes differently to get the correct
                * lexical conventions.
                */

               cp = linebuf;
               while (any(*cp, " \t"))
                       cp++;
               if (*cp == '!') {
                       if (sourcing) {
                               printf("Can't \"!\" while sourcing\n");
                               unstack();
                               continue;
                       }
                       shell(cp+1);
                       continue;
               }
               cp2 = word;
               while (*cp && !any(*cp, " \t0123456789$^.*'\""))
                       *cp2++ = *cp++;
               *cp2 = '\0';

               /*
                * Look up the command; if not found, bitch.
                * Normally, a blank command would map to the
                * first command in the table; while sourcing,
                * however, we ignore blank lines to eliminate
                * confusion.
                */

               if (sourcing && equal(word, ""))
                       continue;
               com = lex(word);
               if (com == NONE) {
                       printf("What?\n");
                       if (sourcing)
                               unstack();
                       continue;
               }

               /*
                * Special case so that quit causes a return to
                * main, who will call the quit code directly.
                * If we are in a source file, just unstack.
                */

               if (com == quitp && sourcing) {
                       unstack();
                       continue;
               }
               if (!edit && com == quitp) {
                       signal(SIGINT, SIG_IGN);
                       return;
               }

               /*
                * Process the arguments to the command, depending
                * on the type he expects.  Default to an error.
                * If we are sourcing an interactive command, it's
                * an error.
                */

               if (!rcvmode && (com->c_argtype & M) == 0) {
                       printf("May not execute \"%s\" while sending\n",
                           com->c_name);
                       unstack();
                       continue;
               }
               if (sourcing && com->c_argtype & I) {
                       printf("May not execute \"%s\" while sourcing\n",
                           com->c_name);
                       unstack();
                       continue;
               }
               e = 1;
               switch (com->c_argtype & ~(P|I|M)) {
               case MSGLIST:
                       /*
                        * A message list defaulting to nearest forward
                        * legal message.
                        */
                       if ((c = getmsglist(cp, msgvec, com->c_msgflags)) < 0)
                               break;
                       if (c  == 0) {
                               *msgvec = first(com->c_msgflags,
                                       com->c_msgmask);
                               msgvec[1] = NULL;
                       }
                       if (*msgvec == NULL) {
                               printf("No applicable messages\n");
                               break;
                       }
                       e = (*com->c_func)(msgvec);
                       break;

               case NDMLIST:
                       /*
                        * A message list with no defaults, but no error
                        * if none exist.
                        */
                       if (getmsglist(cp, msgvec, com->c_msgflags) < 0)
                               break;
                       e = (*com->c_func)(msgvec);
                       break;

               case STRLIST:
                       /*
                        * Just the straight string, with
                        * leading blanks removed.
                        */
                       while (any(*cp, " \t"))
                               cp++;
                       e = (*com->c_func)(cp);
                       break;

               case RAWLIST:
                       /*
                        * A vector of strings, in shell style.
                        */
                       if ((c = getrawlist(cp, arglist)) < 0)
                               break;
                       if (c < com->c_minargs) {
                               printf("%s requires at least %d arg(s)\n",
                                       com->c_name, com->c_minargs);
                               break;
                       }
                       if (c > com->c_maxargs) {
                               printf("%s takes no more than %d arg(s)\n",
                                       com->c_name, com->c_maxargs);
                               break;
                       }
                       e = (*com->c_func)(arglist);
                       break;

               case NOLIST:
                       /*
                        * Just the constant zero, for exiting,
                        * eg.
                        */
                       e = (*com->c_func)(0);
                       break;

               default:
                       panic("Unknown argtype");
               }

               /*
                * Exit the current source file on
                * error.
                */

               if (e && sourcing)
                       unstack();
               if (com == quitp)
                       return;
               if (value("autoprint") != NOSTR && com->c_argtype & P)
                       if ((dot->m_flag & MDELETED) == 0)
                               print(dot);
               if (!sourcing)
                       sawcom = 1;
       }
}

/*
* Find the correct command in the command tble corresponding
* to the passed command "word"
*/

struct cmd *
lex(word)
       char word[];
{
       register struct cmd *cp;
       extern struct cmd cmdtab[];

       for (cp = &cmdtab[0]; cp->c_name != NOSTR; cp++)
               if (isprefix(word, cp->c_name))
                       return(cp);
       return(NONE);
}

/*
* Determine if as1 is a valid prefix of as2.
* Return true if yep.
*/

isprefix(as1, as2)
       char *as1, *as2;
{
       register char *s1, *s2;

       s1 = as1;
       s2 = as2;
       while (*s1++ == *s2)
               if (*s2++ == '\0')
                       return(1);
       return(*--s1 == '\0');
}

/*
* The following gets called on receipt of a rubout.  This is
* to abort printout of a command, mainly.
* Dispatching here when command() is inactive crashes rcv.
* Close all open files except 0, 1, 2, and the temporary.
* The special call to getuserid() is needed so it won't get
* annoyed about losing its open file.
* Also, unstack all source files.
*/

stop()
{
       register FILE *fp;

       signal(SIGINT, SIG_IGN);
       while (sourcing)
               unstack();
       getuserid((char *) -1);
       for (fp = &_iob[0]; fp < &_iob[_NFILE]; fp++) {
               if (fp == stdin || fp == stdout)
                       continue;
               if (fp == itf || fp == otf)
                       continue;
               if (fp == stderr)
                       continue;
               fclose(fp);
       }
       clrbuf(stdout);
       printf("Interrupt\n");
       signal(SIGINT, stop);
       reset();
}

/*
* Announce the presence of the current Mail version,
* give the message count, and print a header listing.
*/

char    *greeting       = "Mail version 1.3 %s.  Type ? for help.\n";

announce()
{
       char *vec[2];
       extern char *version;

       vec[0] = "0";
       vec[1] = NULL;
       if (value("quiet") == NOSTR)
               printf(greeting, version);
       if (msgCount == 1)
               printf("1 message:\n");
       else
               printf("%d messages:\n", msgCount);
       headers(vec);
}

strace() {}

/*
* Print the current version number.
*/

pversion(e)
{
       printf(greeting, version);
       return(0);
}