now uses signal holding facility to avoid losing signals when they must be

[unix-history] / usr / src / usr.bin / mail / lex.c

#

#include "rcv.h"

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

static char *SccsId = "@(#)lex.c	1.17 %G%";

/*
 * Set up editing on the given file name.
 * If isedit is true, we are considered to be editing the file,
 * otherwise we are reading our mail which has signficance for
 * mbox and so forth.
 */

setfile(name, isedit)
	char *name;
{
	FILE *ibuf;
	int i;
	static int shudclob;
	static char efile[128];
	extern char tempMesg[];
	int (*sigs[3])();

	if ((ibuf = fopen(name, "r")) == NULL) {
		if (isedit)
			perror(name);
		else
			printf("No mail for %s\n", myname);
		return(-1);
	}

	/*
	 * Looks like all will be well.  We must now relinquish our
	 * hold on the current set of stuff.  Must ignore signals
	 * while we are reading the new file, else we will ruin
	 * the message[] data structure.
	 */

	sigsave(sigs, SIG_IGN);
	if (shudclob) {
		if (edit)
			edstop();
		else
			quit();
	}

	/*
	 * Copy the messages into /tmp
	 * and set pointers.
	 */

	readonly = 0;
	if ((i = open(name, 1)) < 0)
		readonly++;
	else
		close(i);
	if (shudclob) {
		fclose(itf);
		fclose(otf);
	}
	shudclob = 1;
	edit = isedit;
	strncpy(efile, name, 128);
	editfile = efile;
	if (name != mailname)
		strcpy(mailname, name);
	mailsize = fsize(ibuf);
	if ((otf = fopen(tempMesg, "w")) == NULL) {
		perror(tempMesg);
		exit(1);
	}
	if ((itf = fopen(tempMesg, "r")) == NULL) {
		perror(tempMesg);
		exit(1);
	}
	remove(tempMesg);
	setptr(ibuf);
	setmsize(msgCount);
	fclose(ibuf);
	sigret(sigs);
	shudann = 1;
	sawcom = 0;
	return(0);
}

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

int	*msgvec;

commands()
{
	int prompt, firstsw, stop();
	register int n;
	char linebuf[LINESIZE];
	int hangup(), contin();

	sigset(SIGCONT, contin);
	sighold(SIGCONT);
	if (rcvmode) {
		if (sigset(SIGINT, SIG_IGN) != SIG_IGN)
			sigset(SIGINT, stop);
		if (sigset(SIGHUP, SIG_IGN) != SIG_IGN)
			sigset(SIGHUP, hangup);
	}
	input = stdin;
	prompt = 1;
	if (!intty)
		prompt = 0;
	firstsw = 1;
	for (;;) {
		setexit();
		if (firstsw > 0) {
			firstsw = 0;
			source1(mailrc);
			if (!nosrc)
				source1(MASTER);
		}

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

		if (shudann && !sourcing) {
			shudann = 0;
			if (rcvmode)
				announce(edit);
		}

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

		if (!rcvmode && !sourcing)
			return;
top:
		if (prompt && !sourcing) {
			sigrelse(SIGCONT);
			printf("_\r");
		}
		flush();
		sreset();

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

		n = 0;
		for (;;) {
			if (readline(input, &linebuf[n]) <= 0) {
				if (n != 0)
					break;
				if (sourcing) {
					unstack();
					goto more;
				}
				if (value("ignoreeof") != NOSTR && prompt) {
					printf("Use \"quit\" to quit.\n");
					goto top;
				}
				if (!edit)
					return;
				edstop();
				return;
			}
			if ((n = strlen(linebuf)) == 0)
				break;
			n--;
			if (linebuf[n] != '\\')
				break;
			linebuf[n++] = ' ';
		}
		sighold(SIGCONT);
		if (execute(linebuf, 0))
			return;
more:		;
	}
}

/*
 * Execute a single command.  If the command executed
 * is "quit," then return non-zero so that the caller
 * will know to return back to main, if he cares.
 * Contxt is non-zero if called while composing mail.
 */

execute(linebuf, contxt)
	char linebuf[];
{
	char word[LINESIZE];
	char *arglist[MAXARGC];
	struct cmd *com;
	register char *cp, *cp2;
	register int c;
	int muvec[2];
	int edstop(), e;

	/*
	 * 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();
			return(0);
		}
		shell(cp+1);
		return(0);
	}
	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, ""))
		return(0);
	com = lex(word);
	if (com == NONE) {
		printf("What?\n");
		if (sourcing)
			unstack();
		return(0);
	}

	/*
	 * See if we should execute the command -- if a conditional
	 * we always execute it, otherwise, check the state of cond.
	 */

	if ((com->c_argtype & F) == 0)
		if (cond == CRCV && !rcvmode || cond == CSEND && rcvmode)
			return(0);

	/*
	 * 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->c_func == edstop && sourcing) {
		unstack();
		return(0);
	}
	if (!edit && com->c_func == edstop) {
		sigset(SIGINT, SIG_IGN);
		return(1);
	}

	/*
	 * 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);
		if (sourcing)
			unstack();
		return(0);
	}
	if (sourcing && com->c_argtype & I) {
		printf("May not execute \"%s\" while sourcing\n",
		    com->c_name);
		unstack();
		return(0);
	}
	if (readonly && com->c_argtype & W) {
		printf("May not execute \"%s\" -- message file is read only\n",
		   com->c_name);
		if (sourcing)
			unstack();
		return(0);
	}
	if (contxt && com->c_argtype & R) {
		printf("Cannot recursively invoke \"%s\"\n", com->c_name);
		return(0);
	}
	e = 1;
	switch (com->c_argtype & ~(F|P|I|M|T|W|R)) {
	case MSGLIST:
		/*
		 * A message list defaulting to nearest forward
		 * legal message.
		 */
		if ((c = getmsglist(cp, msgvec, com->c_msgflag)) < 0)
			break;
		if (c  == 0) {
			*msgvec = first(com->c_msgflag,
				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_msgflag) < 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->c_func == edstop)
		return(1);
	if (value("autoprint") != NOSTR && com->c_argtype & P)
		if ((dot->m_flag & MDELETED) == 0) {
			muvec[0] = dot - &message[0] + 1;
			muvec[1] = 0;
			type(muvec);
		}
	if (!sourcing && (com->c_argtype & T) == 0)
		sawcom = 1;
	return(0);
}

/*
 * When we wake up after ^Z, reprint the prompt.
 */
contin(s)
{

	printf("_\r");
	fflush(stdout);
}

/*
 * Branch here on hangup signal and simulate quit.
 */
hangup()
{
	int (*sigs[3])();

	sigsave(sigs);
	if (edit) {
		if (setexit())
			exit(0);
		edstop();
	}
	else
		quit();
	exit(0);
}

/*
 * Set the size of the message vector used to construct argument
 * lists to message list functions.
 */
 
setmsize(sz)
{

	if (msgvec != (int *) 0)
		cfree(msgvec);
	msgvec = (int *) calloc((unsigned) (sz + 1), sizeof *msgvec);
}

/*
 * Find the correct command in the command table 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.
 */

int	inithdr;			/* am printing startup headers */

stop(s)
{
	register FILE *fp;

	noreset = 0;
	if (!inithdr)
		sawcom++;
	inithdr = 0;
	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;
		if (fp == pipef) {
			pclose(pipef);
			pipef = NULL;
			continue;
		}
		fclose(fp);
	}
	if (image >= 0) {
		close(image);
		image = -1;
	}
	clrbuf(stdout);
	printf("Interrupt\n");
	sigrelse(s);
	reset(0);
}

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

char	*greeting	= "Mail version 2.0 %s.  Type ? for help.\n";

announce(pr)
{
	int vec[2], mdot;
	extern char *version;

	mdot = newfileinfo();
	vec[0] = mdot;
	vec[1] = 0;
	if (pr && value("quiet") == NOSTR)
		printf(greeting, version);
	dot = &message[mdot - 1];
	if (msgCount > 0 && !noheader) {
		inithdr++;
		headers(vec);
		inithdr = 0;
	}
}

/*
 * Announce information about the file we are editing.
 * Return a likely place to set dot.
 */

newfileinfo()
{
	register struct message *mp;
	register int u, n, mdot;

	for (mp = &message[0]; mp < &message[msgCount]; mp++)
		if (mp->m_flag & MNEW)
			break;
	if (mp >= &message[msgCount])
		for (mp = &message[0]; mp < &message[msgCount]; mp++)
			if ((mp->m_flag & MREAD) == 0)
				break;
	if (mp < &message[msgCount])
		mdot = mp - &message[0] + 1;
	else
		mdot = 1;
	for (mp = &message[0], n = 0, u = 0; mp < &message[msgCount]; mp++) {
		if (mp->m_flag & MNEW)
			n++;
		if ((mp->m_flag & MREAD) == 0)
			u++;
	}
	printf("\"%s\": ", mailname);
	if (msgCount == 1)
		printf("1 message");
	else
		printf("%d messages", msgCount);
	if (n > 0)
		printf(" %d new", n);
	if (u-n > 0)
		printf(" %d unread", u);
	if (readonly)
		printf(" [Read only]");
	printf("\n");
	return(mdot);
}

strace() {}

/*
 * Print the current version number.
 */

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