lttng: show man page when using command's --help

[lttng-tools.git] / src / common / utils.c

diff --git a/src/common/utils.c b/src/common/utils.c
index d71d92446ce71e14177e26005797211c4f7f0730..df55dc9fb65880db9dc75373c390634849e0fd34 100644 (file)
--- a/src/common/utils.c
+++ b/src/common/utils.c
@@ -1341,7 +1341,40 @@ int utils_truncate_stream_file(int fd, off_t length)
                PERROR("lseek");
                goto end;
        }
-
 end:
        return ret;
 }
+
+static const char *get_man_bin_path(void)
+{
+       char *env_man_path = getenv(DEFAULT_MAN_BIN_PATH_ENV);
+
+       if (env_man_path) {
+               return env_man_path;
+       }
+
+       return DEFAULT_MAN_BIN_PATH;
+}
+
+LTTNG_HIDDEN
+int utils_show_man_page(int section, const char *page_name)
+{
+       char section_string[8];
+       const char *man_bin_path = get_man_bin_path();
+       int ret;
+
+       /* Section integer -> section string */
+       ret = sprintf(section_string, "%d", section);
+       assert(ret > 0 && ret < 8);
+
+       /*
+        * Execute man pager.
+        *
+        * We provide --manpath to man here because LTTng-tools can
+        * 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", "--manpath", MANPATH,
+               section_string, page_name, NULL);
+       return ret;
+}