Remove the hack of scrolling forward and backward with +G1G that

many (jmc@, millert@, espie@, deraadt@) considered revolting.
Instead, when using a pager, since we are using a temporary file
for tags anyway, use another temporary file for the formatted
page(s), as suggested by millert@ and similar to what the traditional
BSD man(1) did, except that we use only one single temporary output
file rather than one for each formatted manual page, such that
searching (both with / and :t) works across all the displayed files.

1 files changed, 33 insertions, 62 deletions

diff --git a/main.c b/main.c
index 66bbfea8..92730522 100644
--- a/main.c
+++ b/main.c
@@ -1,4 +1,4 @@
-/*	$Id: main.c,v 1.243 2015/07/21 03:26:21 schwarze Exp $ */
+/*	$Id: main.c,v 1.244 2015/07/28 18:38:55 schwarze Exp $ */
 /*
  * Copyright (c) 2008-2012 Kristaps Dzonsons <kristaps@bsd.lv>
  * Copyright (c) 2010-2012, 2014, 2015 Ingo Schwarze <schwarze@openbsd.org>
@@ -95,7 +95,6 @@ static	int		  fs_lookup(const struct manpaths *,
 static	void		  fs_search(const struct mansearch *,
 				const struct manpaths *, int, char**,
 				struct manpage **, size_t *);
-static	void		  handle_sigpipe(int);
 static	int		  koptions(int *, char *);
 #if HAVE_SQLITE3
 int			  mandocdb(int, char**);
@@ -105,7 +104,7 @@ static	void		  mmsg(enum mandocerr, enum mandoclevel,
 				const char *, int, int, const char *);
 static	void		  parse(struct curparse *, int, const char *);
 static	void		  passthrough(const char *, int, int);
-static	pid_t		  spawn_pager(void);
+static	pid_t		  spawn_pager(struct tag_files *);
 static	int		  toptions(struct curparse *, char *);
 static	void		  usage(enum argmode) __attribute__((noreturn));
 static	int		  woptions(struct curparse *, char *);
@@ -123,6 +122,7 @@ main(int argc, char *argv[])
 	struct manconf	 conf;
 	struct curparse	 curp;
 	struct mansearch search;
+	struct tag_files *tag_files;
 	char		*auxpaths;
 	char		*defos;
 	unsigned char	*uc;
@@ -136,8 +136,8 @@ main(int argc, char *argv[])
 	int		 fd;
 	int		 show_usage;
 	int		 options;
+	int		 use_pager;
 	int		 c;
-	pid_t		 pager_pid;  /* 0: don't use; 1: not yet spawned. */
 
 	if (argc < 1)
 		progname = "mandoc";
@@ -180,7 +180,8 @@ main(int argc, char *argv[])
 	options = MPARSE_SO | MPARSE_UTF8 | MPARSE_LATIN1;
 	defos = NULL;
 
-	pager_pid = 1;
+	use_pager = 1;
+	tag_files = NULL;
 	show_usage = 0;
 	outmode = OUTMODE_DEF;
 
@@ -194,14 +195,14 @@ main(int argc, char *argv[])
 			conf_file = optarg;
 			break;
 		case 'c':
-			pager_pid = 0;
+			use_pager = 0;
 			break;
 		case 'f':
 			search.argmode = ARG_WORD;
 			break;
 		case 'h':
 			conf.output.synopsisonly = 1;
-			pager_pid = 0;
+			use_pager = 0;
 			outmode = OUTMODE_ALL;
 			break;
 		case 'I':
@@ -277,7 +278,7 @@ main(int argc, char *argv[])
 		switch (search.argmode) {
 		case ARG_FILE:
 			outmode = OUTMODE_ALL;
-			pager_pid = 0;
+			use_pager = 0;
 			break;
 		case ARG_NAME:
 			outmode = OUTMODE_ONE;
@@ -419,8 +420,8 @@ main(int argc, char *argv[])
 	if (search.argmode == ARG_FILE && ! moptions(&options, auxpaths))
 		return((int)MANDOCLEVEL_BADARG);
 
-	if (pager_pid == 1 && isatty(STDOUT_FILENO) == 0)
-		pager_pid = 0;
+	if (use_pager && ! isatty(STDOUT_FILENO))
+		use_pager = 0;
 
 	curp.mchars = mchars_alloc();
 	curp.mp = mparse_alloc(options, curp.wlevel, mmsg,
@@ -433,8 +434,8 @@ main(int argc, char *argv[])
 		mparse_keep(curp.mp);
 
 	if (argc < 1) {
-		if (pager_pid == 1)
-			pager_pid = spawn_pager();
+		if (use_pager)
+			tag_files = tag_init();
 		parse(&curp, STDIN_FILENO, "<stdin>");
 	}
 
@@ -445,8 +446,10 @@ main(int argc, char *argv[])
 			rc = rctmp;
 
 		if (fd != -1) {
-			if (pager_pid == 1)
-				pager_pid = spawn_pager();
+			if (use_pager) {
+				tag_files = tag_init();
+				use_pager = 0;
+			}
 
 			if (resp == NULL)
 				parse(&curp, fd, *argv);
@@ -490,15 +493,14 @@ out:
 	free(defos);
 
 	/*
-	 * If a pager is attached, flush the pipe leading to it
-	 * and signal end of file such that the user can browse
-	 * to the end.  Then wait for the user to close the pager.
+	 * When using a pager, finish writing both temporary files,
+	 * fork it, wait for the user to close it, and clean up.
 	 */
 
-	if (pager_pid != 0 && pager_pid != 1) {
+	if (tag_files != NULL) {
 		fclose(stdout);
 		tag_write();
-		waitpid(pager_pid, NULL, 0);
+		waitpid(spawn_pager(tag_files), NULL, 0);
 		tag_unlink();
 	}
 
@@ -947,22 +949,14 @@ mmsg(enum mandocerr t, enum mandoclevel lvl,
 	fputc('\n', stderr);
 }
 
-static void
-handle_sigpipe(int signum)
-{
-
-	exit((int)rc);
-}
-
 static pid_t
-spawn_pager(void)
+spawn_pager(struct tag_files *tag_files)
 {
 #define MAX_PAGER_ARGS 16
 	char		*argv[MAX_PAGER_ARGS];
 	const char	*pager;
 	char		*cp;
 	size_t		 cmdlen;
-	int		 fildes[2];
 	int		 argc;
 	pid_t		 pager_pid;
 
@@ -991,29 +985,18 @@ spawn_pager(void)
 			break;
 	}
 
-	/* Read all text right away and use the tag file. */
+	/* For more(1) and less(1), use the tag file. */
 
-	for (;;) {
-		if ((cmdlen = strlen(argv[0])) < 4)
-			break;
+	if ((cmdlen = strlen(argv[0])) >= 4) {
 		cp = argv[0] + cmdlen - 4;
-		if (strcmp(cp, "less") && strcmp(cp, "more"))
-			break;
-		if ((cp = tag_init()) == NULL)
-			break;
-		argv[argc++] = mandoc_strdup("+G1G");
-		argv[argc++] = mandoc_strdup("-T");
-		argv[argc++] = cp;
-		break;
+		if (strcmp(cp, "less") == 0 || strcmp(cp, "more") == 0) {
+			argv[argc++] = mandoc_strdup("-T");
+			argv[argc++] = tag_files->tfn;
+		}
 	}
+	argv[argc++] = tag_files->ofn;
 	argv[argc] = NULL;
 
-	if (pipe(fildes) == -1) {
-		fprintf(stderr, "%s: pipe: %s\n",
-		    progname, strerror(errno));
-		return(0);
-	}
-
 	switch (pager_pid = fork()) {
 	case -1:
 		fprintf(stderr, "%s: fork: %s\n",
@@ -1022,29 +1005,17 @@ spawn_pager(void)
 	case 0:
 		break;
 	default:
-		close(fildes[0]);
-		if (dup2(fildes[1], STDOUT_FILENO) == -1) {
-			fprintf(stderr, "%s: dup output: %s\n",
-			    progname, strerror(errno));
-			exit((int)MANDOCLEVEL_SYSERR);
-		}
-		close(fildes[1]);
-		signal(SIGPIPE, handle_sigpipe);
 		return(pager_pid);
 	}
 
 	/* The child process becomes the pager. */
 
-	close(fildes[1]);
-	if (dup2(fildes[0], STDIN_FILENO) == -1) {
-		fprintf(stderr, "%s: dup input: %s\n",
-		    progname, strerror(errno));
+	if (dup2(tag_files->ofd, STDOUT_FILENO) == -1) {
+		fprintf(stderr, "pager: stdout: %s\n", strerror(errno));
 		exit((int)MANDOCLEVEL_SYSERR);
 	}
-	close(fildes[0]);
-
-	/* Hand over to the pager. */
-
+	close(tag_files->ofd);
+	close(tag_files->tfd);
 	execvp(argv[0], argv);
 	fprintf(stderr, "%s: exec %s: %s\n",
 	    progname, argv[0], strerror(errno));