mandoc -a, man, apropos -a, whatis -a now paginate by default

but provide an option -c to not paginate;
taking inspiration from manpage.c, hence adding (c) 2012 kristaps@

3 files changed, 83 insertions, 5 deletions

diff --git a/apropos.1 b/apropos.1
index 43e2c62b..91bed314 100644
--- a/apropos.1
+++ b/apropos.1
@@ -24,7 +24,7 @@
 .Nd search manual page databases
 .Sh SYNOPSIS
 .Nm
-.Op Fl afkw
+.Op Fl acfkw
 .Op Fl C Ar file
 .Op Fl M Ar path
 .Op Fl m Ar path
@@ -71,7 +71,14 @@ just like
 .Xr man 1
 .Fl a
 would.
-In this mode, the options
+If the standard output is a terminal device and
+.Fl c
+is not specified, use
+.Xr more 1
+to paginate them.
+In
+.Fl a
+mode, the options
 .Fl IOTW
 described in the
 .Xr mandoc 1
@@ -82,6 +89,12 @@ Specify an alternative configuration
 in
 .Xr man.conf 5
 format.
+.It Fl c
+In
+.Fl a
+mode, copy the formatted manual pages to the standard output without using
+.Xr more 1
+to paginate them.
 .It Fl f
 Search for all words in
 .Ar expression
diff --git a/main.c b/main.c
index 30a64a83..34da84e4 100644
--- a/main.c
+++ b/main.c
@@ -1,6 +1,6 @@
 /*	$Id$ */
 /*
- * 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 +21,7 @@
 #include <sys/types.h>
 
 #include <assert.h>
+#include <errno.h>
 #include <stdio.h>
 #include <stdint.h>
 #include <stdlib.h>
@@ -84,6 +85,7 @@ 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 +113,7 @@ main(int argc, char *argv[])
 	enum mandoclevel rc;
 	enum outmode	 outmode;
 	int		 show_usage;
+	int		 use_pager;
 	int		 options;
 	int		 c;
 
@@ -145,9 +148,11 @@ 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 +160,9 @@ main(int argc, char *argv[])
 		case 'C':
 			conf_file = optarg;
 			break;
+		case 'c':
+			use_pager = 0;
+			break;
 		case 'f':
 			search.argmode = ARG_WORD;
 			break;
@@ -223,6 +231,7 @@ main(int argc, char *argv[])
 		switch (search.argmode) {
 		case ARG_FILE:
 			outmode = OUTMODE_ALL;
+			use_pager = 0;
 			break;
 		case ARG_NAME:
 			outmode = OUTMODE_ONE;
@@ -319,6 +328,9 @@ 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);
 
 	/*
@@ -621,3 +633,41 @@ mmsg(enum mandocerr t, enum mandoclevel lvl,
 
 	fputc('\n', stderr);
 }
+
+static void
+spawn_pager(void)
+{
+	int	 fildes[2];
+
+	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:
+		close(fildes[1]);
+		if (dup2(fildes[0], STDIN_FILENO) == -1) {
+			fprintf(stderr, "%s: dup input: %s\n",
+			    progname, strerror(errno));
+		} else {
+			execlp("more", "more", "-s", NULL);
+			fprintf(stderr, "%s: exec: %s\n",
+			    progname, strerror(errno));
+		}
+		exit((int)MANDOCLEVEL_SYSERR);
+	}
+}
diff --git a/mandoc.1 b/mandoc.1
index 7e31af4f..2ed605ca 100644
--- a/mandoc.1
+++ b/mandoc.1
@@ -23,7 +23,7 @@
 .Nd format and display UNIX manuals
 .Sh SYNOPSIS
 .Nm mandoc
-.Op Fl V
+.Op Fl acV
 .Sm off
 .Op Fl I Cm os Li = Ar name
 .Sm on
@@ -53,6 +53,21 @@ output.
 .Pp
 The arguments are as follows:
 .Bl -tag -width Ds
+.It Fl a
+If the standard output is a terminal device and
+.Fl c
+is not specified, use
+.Xr more 1
+to paginate the output, just like
+.Xr man 1
+would.
+.It Fl c
+Copy the formatted manual pages to the standard output without using
+.Xr more 1
+to paginate them.
+This is the default.
+It can be specified to override
+.Fl a .
 .Sm off
 .It Fl I Cm os Li = Ar name
 .Sm on