man/man-db-2.6.3-listall.dif

---
 man/man1/man.man1 |    8 ++
 src/man.c         |  180 +++++++++++++++++++++++++++++++++++++++++++++++++++++-
 2 files changed, 186 insertions(+), 2 deletions(-)

--- man/man1/man.man1
+++ man/man1/man.man1	2022-08-17 13:11:29.974677243 +0000
@@ -1226,6 +1226,14 @@ However, some users want to see them any
 .RB $ MAN_KEEP_STDERR
 is set to any non-empty value, error output will be displayed as usual.
 .TP
+.if !'po4a'hide' .BR MAN_POSIXLY_CORRECT
+If many man pages are available corresponding to the requested one,
+.B %man%
+will display them in a list, unless
+.RB $ MAN_POSIXLY_CORRECT
+is set, in which case the first page in the list will be displayed
+automatically.
+.TP
 .if !'po4a'hide' .B MAN_DISABLE_SECCOMP
 On Linux,
 .B %man%
--- src/man.c
+++ src/man.c	2022-08-17 13:10:07.436205495 +0000
@@ -3641,12 +3641,141 @@ static int locate_page (const char *manp
 	return found;
 }
 
+#ifndef PROMPT_IF_MULTIPLE_SECTIONS
+#define PROMPT_IF_MULTIPLE_SECTIONS 2	/* 0: No prompt; 1: Show possible sections; 2: Do prompt for */
+#endif
+
+#if defined(PROMPT_IF_MULTIPLE_SECTIONS) && (PROMPT_IF_MULTIPLE_SECTIONS > 1)
+static sig_atomic_t expired;
+static void handler(int sig)
+{
+	(void)sig;
+	expired++;
+}
+#endif
+
 static int display_pages (struct candidate *candidates)
 {
 	struct candidate *candp;
 	int found = 0;
+	int plain = 0;
+
+#if defined(PROMPT_IF_MULTIPLE_SECTIONS) && (PROMPT_IF_MULTIPLE_SECTIONS > 1)
+	char reqsect[64] = { 0 };
+	ssize_t len = 0;
+	int index = -1;
+	const char *lext;
+	do {
+		struct sigaction sa;
+		int used = 0x2A;
+
+		if (findall)
+			break;
+		if (external)
+			break;
+		if ((troff + catman + (print_where || print_where_cat)))
+			break;
+		if (getenv("MAN_POSIXLY_CORRECT"))
+			break;
+		if (!isatty(STDOUT_FILENO))
+			break;
+		if (!isatty(STDERR_FILENO))
+			break;
+		if (!isatty(STDIN_FILENO))
+			break;
+		if (candidates->next == (struct candidate*)0)
+			break;
+
+		fputs("Man: ", stderr);
+		fputs(_("find all matching manual pages"), stderr);
+		fputs(" (set MAN_POSIXLY_CORRECT to avoid this)", stderr);
+		fputc('\n', stderr);
+
+		lext = NULL;
+		for (candp = candidates; candp; candp = candp->next) {
+			const struct mandata *info = candp->source;
+
+			if (lext && STREQ(lext, info->ext))
+				fprintf(stderr, " %c %s (%s+%d)", used, info->name, info->ext, candp->add_index);
+			else
+				fprintf(stderr, " %c %s (%s)", used, info->name, info->ext);
+
+			if (info->whatis)
+				fprintf(stderr, "\t%s", info->whatis);
+			fputc('\n', stderr);
+			lext = info->ext;
+			used = ' ';
+		}
+		fputs("Man: ", stderr);
+		fputs(_("What manual page do you want?\n"), stderr);
+		fputs("Man: ", stderr);
+		fflush(stderr);
+
+		sigemptyset(&sa.sa_mask);
+		sa.sa_flags = SA_RESETHAND;
+		sa.sa_handler = handler;
+
+		sigaction(SIGALRM, &sa, (struct sigaction*)0);
+
+		alarm(7);
+		len = read(STDIN_FILENO, reqsect, sizeof(reqsect)-1);
+		alarm(0);
+
+		if (expired) {
+			tcflush(STDIN_FILENO, TCIFLUSH);
+			fputc('\n', stderr);
+			fflush(stderr);
+			len = 0;
+			break;
+		}
+		if (len > 0) {
+			char * end;
+			if ((end = strchr(reqsect, '\n')))
+				*end = '\0';
+			if ((end = strchr(reqsect, '+'))) {
+				plain = 1;
+				*end = '\0';
+				if (*++end)
+					index = atoi(end);
+			}
+			reqsect[len] = '\0';
+			len = (ssize_t)strlen(reqsect);
+
+			for (candp = candidates; candp; candp = candp->next) {
+				if (len == 0)
+					break;
+				if (plain) {
+					const char *base = strrchr(candp->path, '/');
+					if (base && !STREQ(base, "/man"))
+						continue;
+				}
+				if (index >= 0 && index != candp->add_index)
+					continue;
+				if ((found = STREQ(reqsect, candp->source->ext)))
+					break;
+			}
+			if (!found)
+				len = 0;
+			found = 0;
+		}
+	} while (0);
+#endif
 
 	for (candp = candidates; candp; candp = candp->next) {
+
+#if defined(PROMPT_IF_MULTIPLE_SECTIONS) && (PROMPT_IF_MULTIPLE_SECTIONS > 1)
+		if (plain) {
+			const char *base = strrchr(candp->path, '/');
+			if (base && !STREQ(base, "/man"))
+				continue;
+		}
+		if (len) {
+			if (!STREQ(reqsect, candp->source->ext))
+				continue;
+			if (index >= 0 && index != candp->add_index)
+				continue;
+		}
+#endif
 		global_manpath = is_global_mandir (candp->path);
 		if (!global_manpath)
 			drop_effective_privs ();
@@ -3668,9 +3797,56 @@ static int display_pages (struct candida
 			regain_effective_privs ();
 
 		if (found && !findall)
-			return found;
+		{
+#if defined(PROMPT_IF_MULTIPLE_SECTIONS) && (PROMPT_IF_MULTIPLE_SECTIONS > 0)
+			if (external)
+				goto out;
+			if ((troff + catman + (print_where || print_where_cat)))
+				goto out;
+# if defined(PROMPT_IF_MULTIPLE_SECTIONS) && (PROMPT_IF_MULTIPLE_SECTIONS == 1)
+			if (getenv("MAN_POSIXLY_CORRECT"))
+				goto out;
+# endif
+			if (!isatty(STDOUT_FILENO))
+				goto out;
+			if (!isatty(STDERR_FILENO))
+				goto out;
+			/*
+			 * Should be able to use the output as done by whatis(1)
+			 */
+# if defined(PROMPT_IF_MULTIPLE_SECTIONS) && (PROMPT_IF_MULTIPLE_SECTIONS == 1)
+			if (candp->next)
+# else
+			if (candp->next && getenv("MAN_POSIXLY_CORRECT"))
+# endif
+			{
+				int used = 0x2A;
+
+				fputs("Man: ", stderr);
+				fputs(_("find all matching manual pages"), stderr);
+				fputc('\n', stderr);
+
+				lext = NULL;
+				do {
+					struct mandata *info = candp->source;
+					if (lext && STREQ(lext, info->ext))
+						fprintf(stderr, " %c %s (%s+%d)", used, info->name, info->ext, candp->add_index);
+					else
+						fprintf(stderr, " %c %s (%s)", used, info->name, info->ext);
+					if (info->whatis) {
+						fprintf(stderr, "\t%s", info->whatis);
+					}
+					fputc('\n', stderr);
+					lext = info->ext;
+					used = ' ';
+				} while ((candp = candp->next));
+				fflush(stderr);
+			}
+#endif
+			goto out;
+		}
 	}
-
+out:
 	return found;
 }