man: new applet. ~600 bytes.

3 files changed, 158 insertions, 0 deletions

diff --git a/miscutils/Config.in b/miscutils/Config.in
index c6c1490df..06cac14ab 100644
--- a/miscutils/Config.in
+++ b/miscutils/Config.in
@@ -372,6 +372,12 @@ config FEATURE_MAKEDEVS_TABLE
 
 endchoice
 
+config MAN
+        bool "man"
+        default n
+        help
+          Format and display manual pages.
+
 config MICROCOM
         bool "microcom"
         default n
diff --git a/miscutils/Kbuild b/miscutils/Kbuild
index 513c03882..ba2a0dc14 100644
--- a/miscutils/Kbuild
+++ b/miscutils/Kbuild
@@ -19,6 +19,7 @@ lib-$(CONFIG_HDPARM)      += hdparm.o
 lib-$(CONFIG_LAST)        += last.o
 lib-$(CONFIG_LESS)        += less.o
 lib-$(CONFIG_MAKEDEVS)    += makedevs.o
+lib-$(CONFIG_MAN)         += man.o
 lib-$(CONFIG_MICROCOM)    += microcom.o
 lib-$(CONFIG_MOUNTPOINT)  += mountpoint.o
 lib-$(CONFIG_MT)          += mt.o
diff --git a/miscutils/man.c b/miscutils/man.c
new file mode 100644
index 000000000..ed31b66c7
--- /dev/null
+++ b/miscutils/man.c
@@ -0,0 +1,151 @@
+/* mini man implementation for busybox
+ * Copyright (C) 2008 Denys Vlasenko <vda.linux@googlemail.com>
+ * Licensed under GPLv2, see file LICENSE in this tarball for details.
+ */
+
+#include "libbb.h"
+
+enum {
+        OPT_a = 1, /* all */
+        OPT_w = 2, /* print path */
+};
+
+/* This is what I see on my desktop system deing executed:
+
+(
+echo ".ll 12.4i"
+echo ".nr LL 12.4i"
+echo ".pl 1100i"
+gunzip -c '/usr/man/man1/bzip2.1.gz'
+echo ".\\\""
+echo ".pl \n(nlu+10"
+) | gtbl | nroff -Tlatin1 -mandoc | less
+
+*/
+
+static int run_pipe(const char *unpacker, const char *pager, char *man_filename)
+{
+        char *cmd;
+
+        if (access(man_filename, R_OK) != 0)
+                return 0;
+
+        if (option_mask32 & OPT_w) {
+                puts(man_filename);
+                return 1;
+        }
+
+        cmd = xasprintf("%s '%s' | gtbl | nroff -Tlatin1 -mandoc | %s",
+                        unpacker, man_filename, pager);
+        system(cmd);
+        free(cmd);
+        return 1;
+}
+
+/* man_filename is of the form "/dir/dir/dir/name.s.bz2" */
+static int show_manpage(const char *pager, char *man_filename)
+{
+        int len;
+
+        if (run_pipe("bunzip2 -c", pager, man_filename))
+                return 1;
+
+        len = strlen(man_filename) - 1;
+
+        man_filename[len] = '\0'; /* ".bz2" -> ".gz" */
+        man_filename[len - 2] = 'g';
+        if (run_pipe("gunzip -c", pager, man_filename))
+                return 1;
+
+        man_filename[len - 3] = '\0'; /* ".gz" -> "" */
+        if (run_pipe("cat", pager, man_filename))
+                return 1;
+
+        return 0;
+}
+
+int man_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
+int man_main(int argc ATTRIBUTE_UNUSED, char **argv)
+{
+        FILE *cf;
+        const char *pager;
+        char *man_path, *sec_list;
+        char *cur_path, *cur_sect;
+        char *line, *value;
+        int opt;
+
+        opt_complementary = "-1"; /* at least one argument */
+        opt = getopt32(argv, "+aw");
+        argv += optind;
+
+        sec_list = xstrdup("1:2:3:4:5:6:7:8:9");
+        man_path = xstrdup(getenv("MANPATH"));
+        pager = getenv("MANPAGER");
+        if (!pager) {
+                pager = getenv("PAGER");
+                if (!pager)
+                        pager = "more";
+        }
+
+        /* Parse man.conf */
+        cf = fopen_or_warn("/etc/man.conf", "r");
+        if (cf) {
+                /* go through man configuration file and search relevant paths, sections */
+                while ((line = xmalloc_fgetline(cf)) != NULL) {
+                        trim(line); /* remove whitespace at the beginning/end */
+                        if (isspace(line[7])) {
+                                line[7] = '\0';
+                                value = skip_whitespace(&line[8]);
+                                *skip_non_whitespace(value) = '\0';
+                                if (strcmp("MANPATH", line) == 0) {
+                                        free(man_path);
+                                                man_path = xstrdup(value);
+                                }
+                                if (strcmp("MANSECT", line) == 0) {
+                                        free(sec_list);
+                                        sec_list = xstrdup(value);
+                                }
+                        }
+                        free(line);
+                }
+                fclose(cf);
+        }
+
+        do { /* for each argv[] */
+                cur_path = man_path;
+                do { /* for each MANPATH item */
+                        char *next_path = strchrnul(cur_path, ':');
+                        int path_len = next_path - cur_path;
+
+                        cur_sect = sec_list;
+                        do { /* for each section */
+                                char *next_sect = strchrnul(cur_sect, ':');
+                                int sect_len = next_sect - cur_sect;
+
+                                char *man_filename = xasprintf("%.*s/man%.*s/%s.%.*s" ".bz2",
+                                                        path_len, cur_path,
+                                                        sect_len, cur_sect,
+                                                        *argv,
+                                                        sect_len, cur_sect);
+                                if (show_manpage(pager, man_filename)) {
+                                        if (!(opt & OPT_a)) {
+                                                goto next_arg;
+                                        }
+                                }
+                                free(man_filename);
+
+                                cur_sect = next_sect;
+                                while (*cur_sect == ':')
+                                        cur_sect++;
+                        } while (*cur_sect);
+
+                        cur_path = next_path;
+                        while (*cur_path == ':')
+                                cur_path++;
+                } while (*cur_path);
+ next_arg:
+                argv++;
+        } while (*argv);
+
+        return EXIT_SUCCESS;
+}