From: Olivier Dion <odion@efficios.com>
Date: Mon, 2 Oct 2023 19:09:44 +0000 (-0400)
Subject: utils: Allow users to define LTTNG_MANPATH
X-Git-Url: https://git.lttng.org/?p=lttng-tools.git;a=commitdiff_plain;h=ef4a570db1fbc6ffa5f645e76c4cf25e8098aee1

utils: Allow users to define LTTNG_MANPATH

Currently, the configured value `MANPATH` is used when executing `man`.
This forces `lttng --help` to use man pages where they will be
installed, even with the `pre-inst-env` script.

Instead, let the user provide a `LTTNG_MANPATH` environment variable. If
not defined, fallback to the configured `MANPATH`.

This allows developers to do:

  $ ./pre-inst-env lttng --help

to read the locally generated man pages where the `pre-inst-env` script
was generated.

Also adding the `LTTNG_MAN_BIN_PATH` to `pre-inst-env` since `man` could
be installed someplace else.

Change-Id: I32d9af480737bb80732dc5d690f947242aacac4f
Signed-off-by: Olivier Dion <odion@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
---

diff --git a/pre-inst-env.in b/pre-inst-env.in
index 1a0641d6a..f779aa453 100644
--- a/pre-inst-env.in
+++ b/pre-inst-env.in
@@ -28,4 +28,12 @@ export PATH
 MANPATH="$builddir/doc/man"
 export MANPATH
 
+# Use local path to search manual pages for lttng --help.
+LTTNG_MANPATH="$builddir/doc/man"
+export LTTNG_MANPATH
+
+# Use system man instead of /usr/bin/man.
+LTTNG_MAN_BIN_PATH=$(type -p man)
+export LTTNG_MAN_BIN_PATH
+
 exec "$@"
diff --git a/src/common/defaults.hpp b/src/common/defaults.hpp
index 4b4d902dd..149c483ec 100644
--- a/src/common/defaults.hpp
+++ b/src/common/defaults.hpp
@@ -30,6 +30,9 @@
 /* Environment variable to set man pager binary path. */
 #define DEFAULT_MAN_BIN_PATH_ENV "LTTNG_MAN_BIN_PATH"
 
+/* Environment variable to set man manpath. */
+#define DEFAULT_MANPATH "LTTNG_MANPATH"
+
 /* Default man pager binary path. */
 #define DEFAULT_MAN_BIN_PATH "/usr/bin/man"
 
diff --git a/src/common/utils.cpp b/src/common/utils.cpp
index 0f6e0362f..7cd61c049 100644
--- a/src/common/utils.cpp
+++ b/src/common/utils.cpp
@@ -1020,10 +1020,23 @@ static const char *get_man_bin_path()
 	return DEFAULT_MAN_BIN_PATH;
 }
 
+static const char *get_manpath()
+{
+	char *manpath = lttng_secure_getenv(DEFAULT_MANPATH);
+
+	if (manpath) {
+		return manpath;
+	}
+
+	/* As defined during configuration. */
+	return MANPATH;
+}
+
 int utils_show_help(int section, const char *page_name, const char *help_msg)
 {
 	char section_string[8];
 	const char *man_bin_path = get_man_bin_path();
+	const char *manpath = get_manpath();
 	int ret = 0;
 
 	if (help_msg) {
@@ -1042,7 +1055,7 @@ int utils_show_help(int section, const char *page_name, const char *help_msg)
 	 * be installed outside /usr, in which case its man pages are
 	 * not located in the default /usr/share/man directory.
 	 */
-	ret = execlp(man_bin_path, "man", "-M", MANPATH, section_string, page_name, NULL);
+	ret = execlp(man_bin_path, "man", "-M", manpath, section_string, page_name, NULL);
 
 end:
 	return ret;