===================================================================
RCS file: /cvs/mandoc/main.c,v
retrieving revision 1.182
retrieving revision 1.185
diff -u -p -r1.182 -r1.185
--- mandoc/main.c	2014/08/21 00:32:15	1.182
+++ mandoc/main.c	2014/08/22 18:07:15	1.185
@@ -1,6 +1,6 @@
-/*	$Id: main.c,v 1.182 2014/08/21 00:32:15 schwarze Exp $ */
+/*	$Id: main.c,v 1.185 2014/08/22 18:07:15 schwarze Exp $ */
 /*
- * Copyright (c) 2008, 2009, 2010, 2011 Kristaps Dzonsons <kristaps@bsd.lv>
+ * Copyright (c) 2008-2012 Kristaps Dzonsons <kristaps@bsd.lv>
  * Copyright (c) 2010, 2011, 2012, 2014 Ingo Schwarze <schwarze@openbsd.org>
  * Copyright (c) 2010 Joerg Sonnenberger <joerg@netbsd.org>
  *
@@ -21,6 +21,8 @@
 #include <sys/types.h>
 
 #include <assert.h>
+#include <ctype.h>
+#include <errno.h>
 #include <stdio.h>
 #include <stdint.h>
 #include <stdlib.h>
@@ -84,6 +86,7 @@ static	void		  mmsg(enum mandocerr, enum mandoclevel,
 				const char *, int, int, const char *);
 static	void		  parse(struct curparse *, int,
 				const char *, enum mandoclevel *);
+static	void		  spawn_pager(void);
 static	int		  toptions(struct curparse *, char *);
 static	void		  usage(enum argmode) __attribute__((noreturn));
 static	void		  version(void) __attribute__((noreturn));
@@ -111,6 +114,7 @@ main(int argc, char *argv[])
 	enum mandoclevel rc;
 	enum outmode	 outmode;
 	int		 show_usage;
+	int		 use_pager;
 	int		 options;
 	int		 c;
 
@@ -145,9 +149,11 @@ main(int argc, char *argv[])
 	options = MPARSE_SO;
 	defos = NULL;
 
+	use_pager = 1;
 	show_usage = 0;
 	outmode = OUTMODE_DEF;
-	while (-1 != (c = getopt(argc, argv, "aC:fI:ikM:m:O:S:s:T:VW:w"))) {
+
+	while (-1 != (c = getopt(argc, argv, "aC:cfI:ikM:m:O:S:s:T:VW:w"))) {
 		switch (c) {
 		case 'a':
 			outmode = OUTMODE_ALL;
@@ -155,6 +161,9 @@ main(int argc, char *argv[])
 		case 'C':
 			conf_file = optarg;
 			break;
+		case 'c':
+			use_pager = 0;
+			break;
 		case 'f':
 			search.argmode = ARG_WORD;
 			break;
@@ -219,10 +228,13 @@ main(int argc, char *argv[])
 	if (show_usage)
 		usage(search.argmode);
 
+	/* Postprocess options. */
+
 	if (outmode == OUTMODE_DEF) {
 		switch (search.argmode) {
 		case ARG_FILE:
 			outmode = OUTMODE_ALL;
+			use_pager = 0;
 			break;
 		case ARG_NAME:
 			outmode = OUTMODE_ONE;
@@ -233,12 +245,25 @@ main(int argc, char *argv[])
 		}
 	}
 
+	/* Parse arguments. */
+
 	argc -= optind;
 	argv += optind;
 #if HAVE_SQLITE3
 	auxargv = NULL;
 #endif
 
+	/* Quirk for a man(1) section argument without -s. */
+
+	if (search.argmode == ARG_NAME &&
+	    argv[0] != NULL &&
+	    isdigit((unsigned char)argv[0][0]) &&
+	    (argv[0][1] == '\0' || !strcmp(argv[0], "3p"))) {
+		search.sec = argv[0];
+		argv++;
+		argc--;
+	}
+
 	rc = MANDOCLEVEL_OK;
 
 	/* man(1), whatis(1), apropos(1) */
@@ -319,6 +344,9 @@ main(int argc, char *argv[])
 	if ( ! moptions(&options, auxpaths))
 		return((int)MANDOCLEVEL_BADARG);
 
+	if (use_pager && isatty(STDOUT_FILENO))
+		spawn_pager();
+
 	curp.mp = mparse_alloc(options, curp.wlevel, mmsg, defos);
 
 	/*
@@ -620,4 +648,80 @@ mmsg(enum mandocerr t, enum mandoclevel lvl,
 		fprintf(stderr, ": %s", msg);
 
 	fputc('\n', stderr);
+}
+
+static void
+spawn_pager(void)
+{
+#define MAX_PAGER_ARGS 16
+	char		*argv[MAX_PAGER_ARGS];
+	const char	*pager;
+	char		*cp;
+	int		 fildes[2];
+	int		 argc;
+
+	if (pipe(fildes) == -1) {
+		fprintf(stderr, "%s: pipe: %s\n",
+		    progname, strerror(errno));
+		return;
+	}
+
+	switch (fork()) {
+	case -1:
+		fprintf(stderr, "%s: fork: %s\n",
+		    progname, strerror(errno));
+		exit((int)MANDOCLEVEL_SYSERR);
+	case 0:
+		close(fildes[0]);
+		if (dup2(fildes[1], STDOUT_FILENO) == -1) {
+			fprintf(stderr, "%s: dup output: %s\n",
+			    progname, strerror(errno));
+			exit((int)MANDOCLEVEL_SYSERR);
+		}
+		return;
+	default:
+		break;
+	}
+
+	/* The original process becomes the pager. */
+
+	close(fildes[1]);
+	if (dup2(fildes[0], STDIN_FILENO) == -1) {
+		fprintf(stderr, "%s: dup input: %s\n",
+		    progname, strerror(errno));
+		exit((int)MANDOCLEVEL_SYSERR);
+	}
+
+	pager = getenv("MANPAGER");
+	if (pager == NULL || *pager == '\0')
+		pager = getenv("PAGER");
+	if (pager == NULL || *pager == '\0')
+		pager = "/usr/bin/more -s";
+	cp = mandoc_strdup(pager);
+
+	/*
+	 * Parse the pager command into words.
+	 * Intentionally do not do anything fancy here.
+	 */
+
+	argc = 0;
+	while (argc + 1 < MAX_PAGER_ARGS) {
+		argv[argc++] = cp;
+		cp = strchr(cp, ' ');
+		if (cp == NULL)
+			break;
+		*cp++ = '\0';
+		while (*cp == ' ')
+			cp++;
+		if (*cp == '\0')
+			break;
+	}
+	argv[argc] = NULL;
+
+	/* Hand over to the pager. */
+
+	execvp(argv[0], argv);
+	fprintf(stderr, "%s: exec: %s\n",
+	    progname, strerror(errno));
+	exit((int)MANDOCLEVEL_SYSERR);
 }