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LU-8621 utils: cmd help to stdout or short cmd error
[fs/lustre-release.git] / libcfs / libcfs / util / parser.c
index dbb3e92..be97809 100644 (file)
@@ -1,8 +1,8 @@
-/* -*- mode: c; c-basic-offset: 8; indent-tabs-mode: nil; -*-
- * vim:expandtab:shiftwidth=8:tabstop=8:
- *
+/*
  * Copyright (C) 2001 Cluster File Systems, Inc.
  *
+ * Copyright (c) 2014, 2017, Intel Corporation.
+ *
  *   This file is part of Lustre, http://www.sf.net/projects/lustre/
  *
  *   Lustre is free software; you can redistribute it and/or
  *
  */
 
-#include <libcfs/libcfsutil.h>
-
-static command_t * top_level;           /* Top level of commands, initialized by
-                                    * InitParser                              */
-static char * parser_prompt = NULL;/* Parser prompt, set by InitParser      */
-static int done;                   /* Set to 1 if user types exit or quit   */
-static int ignore_errors;       /* Normally, the parser will quit when
-                                   an error occurs in non-interacive
-                                   mode. Setting this to non-zero will
-                                   force it to keep buggering on. */
-
+#include <stddef.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <assert.h>
+#include <ctype.h>
+#include <errno.h>
+#include <getopt.h>
+#include <malloc.h>
+#ifdef HAVE_LIBREADLINE
+# include <readline/history.h>
+# include <readline/readline.h>
+#endif /* HAVE_LIBREADLINE */
+#include <string.h>
+#include <unistd.h>
+
+#include <libcfs/util/parser.h>
+#include <linux/lustre/lustre_ver.h>
+
+/* Top level of commands, initialized by InitParser */
+static command_t *top_level;
+/* Parser prompt, set by InitParser */
+static char *parser_prompt;
+/* Set to 1 if user types exit or quit */
+static int done;
+/*
+ * Normally, the parser will quit when an error occurs in non-interacive
+ * mode. Setting this to non-zero will force it to keep buggering on.
+ */
+static int ignore_errors;
 
 /* static functions */
 static char *skipwhitespace(char *s);
 static char *skiptowhitespace(char *s);
 static command_t *find_cmd(char *name, command_t cmds[], char **next);
 static int process(char *s, char **next, command_t *lookup, command_t **result,
-                   char **prev);
-static void print_commands(char *str, command_t *table);
+                  char **prev);
 
-static char * skipwhitespace(char * s)
+static char *skipwhitespace(char *s)
 {
-        char * t;
-        int    len;
+       char *t;
+       int len;
 
-        len = (int)strlen(s);
-        for (t = s; t <= s + len && isspace(*t); t++);
-        return(t);
+       len = (int)strlen(s);
+       for (t = s; t <= s + len && isspace(*t); t++)
+               ;
+       return t;
 }
 
-
-static char * skiptowhitespace(char * s)
+static char *skiptowhitespace(char *s)
 {
-        char * t;
+       char *t;
 
-        for (t = s; *t && !isspace(*t); t++);
-        return(t);
+       for (t = s; *t && !isspace(*t); t++)
+               ;
+       return t;
 }
 
 static int line2args(char *line, char **argv, int maxargs)
 {
-        char *arg;
-        int i = 0;
-
-        arg = strtok(line, " \t");
-        if ( arg ) {
-                argv[i] = arg;
-                i++;
-        } else
-                return 0;
-
-        while( (arg = strtok(NULL, " \t")) && (i <= maxargs)) {
-                argv[i] = arg;
-                i++;
-        }
-        return i;
+       char *arg;
+       int i = 0;
+
+       arg = strtok(line, " \t");
+       if (!arg || maxargs < 1)
+               return 0;
+
+       argv[i++] = arg;
+       while ((arg = strtok(NULL, " \t")) != NULL && i < maxargs)
+               argv[i++] = arg;
+       return i;
 }
 
 /* find a command -- return it if unique otherwise print alternatives */
 static command_t *Parser_findargcmd(char *name, command_t cmds[])
 {
-        command_t *cmd;
+       command_t *cmd;
 
-        for (cmd = cmds; cmd->pc_name; cmd++) {
-                if (strcmp(name, cmd->pc_name) == 0)
-                        return cmd;
-        }
-        return NULL;
+       for (cmd = cmds; cmd->pc_name; cmd++) {
+               if (strcmp(name, cmd->pc_name) == 0)
+                       return cmd;
+       }
+       return NULL;
 }
 
 void Parser_ignore_errors(int ignore)
 {
-        ignore_errors = ignore;
+       ignore_errors = ignore;
 }
 
 int Parser_execarg(int argc, char **argv, command_t cmds[])
 {
-        command_t *cmd;
-
-        cmd = Parser_findargcmd(argv[0], cmds);
-        if ( cmd ) {
-                int rc = (cmd->pc_func)(argc, argv);
-                if (rc == CMD_HELP)
-                        fprintf(stderr, "%s\n", cmd->pc_help);
-                return rc;
-        } else {
-               printf("Try interactive use without arguments or use one of:\n");
-                for (cmd = cmds; cmd->pc_name; cmd++)
-                        printf("\"%s\"\n", cmd->pc_name);
-                printf("as argument.\n");
-        }
-        return -1;
+       command_t *cmd;
+
+       cmd = Parser_findargcmd(argv[0], cmds);
+       if (cmd && cmd->pc_func) {
+               int rc = cmd->pc_func(argc, argv);
+
+               if (rc == CMD_HELP) {
+                       fprintf(stdout, "%s\n", cmd->pc_help);
+                       fflush(stdout);
+               }
+               return rc;
+       }
+       fprintf(stderr,
+               "%s: '%s' is not a valid command. See '%s --list-commands'.\n",
+               program_invocation_short_name, argv[0],
+               program_invocation_short_name);
+
+       return -1;
 }
 
-/* returns the command_t * (NULL if not found) corresponding to a
-   _partial_ match with the first token in name.  It sets *next to
-   point to the following token. Does not modify *name. */
-static command_t * find_cmd(char * name, command_t cmds[], char ** next)
+/*
+ * Returns the command_t * (NULL if not found) corresponding to a
+ * _partial_ match with the first token in name.  It sets *next to
+ * point to the following token. Does not modify *name.
+ */
+static command_t *find_cmd(char *name, command_t cmds[], char **next)
 {
-        int    i, len;
-
-        if (!cmds || !name )
-                return NULL;
-
-        /* This sets name to point to the first non-white space character,
-           and next to the first whitespace after name, len to the length: do
-           this with strtok*/
-        name = skipwhitespace(name);
-        *next = skiptowhitespace(name);
-        len = (int)(*next - name);
-        if (len == 0)
-                return NULL;
-
-        for (i = 0; cmds[i].pc_name; i++) {
-                if (strncasecmp(name, cmds[i].pc_name, len) == 0) {
-                        *next = skipwhitespace(*next);
-                        return(&cmds[i]);
-                }
-        }
-        return NULL;
+       int i, len;
+
+       if (!cmds || !name)
+               return NULL;
+
+       /*
+        * This sets name to point to the first non-white space character,
+        * and next to the first whitespace after name, len to the length: do
+        * this with strtok
+        */
+       name = skipwhitespace(name);
+       *next = skiptowhitespace(name);
+       len = (int)(*next - name);
+       if (len == 0)
+               return NULL;
+
+       for (i = 0; cmds[i].pc_name; i++) {
+               if (strncasecmp(name, cmds[i].pc_name, len) == 0) {
+                       *next = skipwhitespace(*next);
+                       return &cmds[i];
+               }
+       }
+       return NULL;
 }
 
-/* Recursively process a command line string s and find the command
-   corresponding to it. This can be ambiguous, full, incomplete,
-   non-existent. */
-static int process(char *s, char ** next, command_t *lookup,
-                   command_t **result, char **prev)
+/*
+ * Recursively process a command line string s and find the command
+ * corresponding to it. This can be ambiguous, full, incomplete,
+ * non-existent.
+ */
+static int process(char *s, char **next, command_t *lookup,
+                  command_t **result, char **prev)
 {
-        *result = find_cmd(s, lookup, next);
-        *prev = s;
-
-        /* non existent */
-        if (!*result)
-                return CMD_NONE;
-
-        /* found entry: is it ambigous, i.e. not exact command name and
-           more than one command in the list matches.  Note that find_cmd
-           points to the first ambiguous entry */
-        if (strncasecmp(s, (*result)->pc_name, strlen((*result)->pc_name))) {
-                char *another_next;
-                command_t *another_result = find_cmd(s, (*result) + 1,
-                                                     &another_next);
-                int found_another = 0;
-
-                while (another_result) {
-                        if (strncasecmp(s, another_result->pc_name,
-                                        strlen(another_result->pc_name)) == 0){
-                                *result = another_result;
-                                *next = another_next;
-                                goto got_it;
-                        }
-                        another_result = find_cmd(s, another_result + 1,
-                                                  &another_next);
-                        found_another = 1;
-                }
-                if (found_another)
-                        return CMD_AMBIG;
-        }
+       *result = find_cmd(s, lookup, next);
+       *prev = s;
+
+       /* non existent */
+       if (!*result)
+               return CMD_NONE;
+
+       /*
+        * found entry: is it ambigous, i.e. not exact command name and
+        * more than one command in the list matches.  Note that find_cmd
+        * points to the first ambiguous entry
+        */
+       if (strncasecmp(s, (*result)->pc_name, strlen((*result)->pc_name))) {
+               char *another_next;
+               int found_another = 0;
+
+               command_t *another_result = find_cmd(s, (*result) + 1,
+                                                    &another_next);
+               while (another_result) {
+                       if (strncasecmp(s, another_result->pc_name,
+                                       strlen(another_result->pc_name)) == 0) {
+                               *result = another_result;
+                               *next = another_next;
+                               goto got_it;
+                       }
+                       another_result = find_cmd(s, another_result + 1,
+                                                 &another_next);
+                       found_another = 1;
+               }
+               if (found_another)
+                       return CMD_AMBIG;
+       }
 
 got_it:
-        /* found a unique command: component or full? */
-        if ( (*result)->pc_func ) {
-                return CMD_COMPLETE;
-        } else {
-                if ( *next == '\0' ) {
-                        return CMD_INCOMPLETE;
-                } else {
-                        return process(*next, next, (*result)->pc_sub_cmd,
-                                       result, prev);
-                }
-        }
+       /* found a unique command: component or full? */
+       if ((*result)->pc_func)
+               return CMD_COMPLETE;
+
+       if (**next == '\0')
+               return CMD_INCOMPLETE;
+       return process(*next, next, (*result)->pc_sub_cmd,
+                      result, prev);
 }
 
 #ifdef HAVE_LIBREADLINE
-static command_t * match_tbl;   /* Command completion against this table */
-static char * command_generator(const char * text, int state)
+static command_t *match_tbl; /* Command completion against this table */
+static char *command_generator(const char *text, int state)
 {
-        static int index,
-                len;
-        char       *name;
-
-        /* Do we have a match table? */
-        if (!match_tbl)
-                return NULL;
-
-        /* If this is the first time called on this word, state is 0 */
-        if (!state) {
-                index = 0;
-                len = (int)strlen(text);
-        }
-
-        /* Return next name in the command list that paritally matches test */
-        while ( (name = (match_tbl + index)->pc_name) ) {
-                index++;
-
-                if (strncasecmp(name, text, len) == 0) {
-                        return(strdup(name));
-                }
-        }
-
-        /* No more matches */
-        return NULL;
+       static int index, len;
+       char *name;
+
+       /* Do we have a match table? */
+       if (!match_tbl)
+               return NULL;
+
+       /* If this is the first time called on this word, state is 0 */
+       if (!state) {
+               index = 0;
+               len = (int)strlen(text);
+       }
+
+       /* Return next name in the command list that paritally matches test */
+       while ((name = (match_tbl + index)->pc_name)) {
+               index++;
+
+               if (strncasecmp(name, text, len) == 0)
+                       return strdup(name);
+       }
+
+       /* No more matches */
+       return NULL;
 }
 
 /* probably called by readline */
-static char **command_completion(char * text, int start, int end)
+static char **command_completion(const char *text, int start, int end)
 {
-        command_t   * table;
-        char        * pos;
+       command_t *table;
+       char *pos;
 
-        match_tbl = top_level;
-        
-        for (table = find_cmd(rl_line_buffer, match_tbl, &pos);
-             table; table = find_cmd(pos, match_tbl, &pos)) 
-        {
+       match_tbl = top_level;
 
-                if (*(pos - 1) == ' ') match_tbl = table->pc_sub_cmd;
-        }
+       for (table = find_cmd(rl_line_buffer, match_tbl, &pos);
+            table; table = find_cmd(pos, match_tbl, &pos)) {
+               if (*(pos - 1) == ' ')
+                       match_tbl = table->pc_sub_cmd;
+       }
 
-        return completion_matches(text, command_generator);
+       return rl_completion_matches(text, command_generator);
 }
 #endif
 
 /* take a string and execute the function or print help */
-int execute_line(char * line)
+static int execute_line(char *line)
 {
-        command_t         *cmd, *ambig;
-        char *prev;
-        char *next, *tmp;
-        char *argv[MAXARGS];
-        int         i;
-        int rc = 0;
-
-        switch (process(line, &next, top_level, &cmd, &prev)) {
-        case CMD_AMBIG:
-                fprintf(stderr, "Ambiguous command \'%s\'\nOptions: ", line);
-                while( (ambig = find_cmd(prev, cmd, &tmp)) ) {
-                        fprintf(stderr, "%s ", ambig->pc_name);
-                        cmd = ambig + 1;
-                }
-                fprintf(stderr, "\n");
-                break;
-        case CMD_NONE:
-                fprintf(stderr, "No such command, type help\n");
-                break;
-        case CMD_INCOMPLETE:
-                fprintf(stderr,
-                        "'%s' incomplete command.  Use '%s x' where x is one of:\n",
-                        line, line);
-                fprintf(stderr, "\t");
-                for (i = 0; cmd->pc_sub_cmd[i].pc_name; i++) {
-                        fprintf(stderr, "%s ", cmd->pc_sub_cmd[i].pc_name);
-                }
-                fprintf(stderr, "\n");
-                break;
-        case CMD_COMPLETE:
-                i = line2args(line, argv, MAXARGS);
-                rc = (cmd->pc_func)(i, argv);
-
-                if (rc == CMD_HELP)
-                        fprintf(stderr, "%s\n", cmd->pc_help);
-
-                break;
-        }
-
-        return rc;
+       command_t *cmd, *ambig;
+       char *prev;
+       char *next, *tmp;
+       char *argv[MAXARGS];
+       int i;
+       int rc = 0;
+
+       switch (process(line, &next, top_level, &cmd, &prev)) {
+       case CMD_AMBIG:
+               fprintf(stderr, "Ambiguous command \'%s\'\nOptions: ", line);
+               while ((ambig = find_cmd(prev, cmd, &tmp))) {
+                       fprintf(stderr, "%s ", ambig->pc_name);
+                       cmd = ambig + 1;
+               }
+               fprintf(stderr, "\n");
+               break;
+       case CMD_NONE:
+               fprintf(stderr, "No such command, type help\n");
+               break;
+       case CMD_INCOMPLETE:
+               fprintf(stderr,
+                       "'%s' incomplete command.  Use '%s x' where x is one of:\n",
+                       line, line);
+               fprintf(stderr, "\t");
+               for (i = 0; cmd->pc_sub_cmd[i].pc_name; i++)
+                       fprintf(stderr, "%s ", cmd->pc_sub_cmd[i].pc_name);
+               fprintf(stderr, "\n");
+               break;
+       case CMD_COMPLETE:
+               optind = 0;
+               i = line2args(line, argv, MAXARGS);
+               rc = cmd->pc_func(i, argv);
+
+               if (rc == CMD_HELP) {
+                       fprintf(stdout, "%s\n", cmd->pc_help);
+                       fflush(stdout);
+               }
+
+               break;
+       }
+
+       return rc;
 }
 
-int
-noop_fn ()
-{
-        return (0);
-}
+#ifdef HAVE_LIBREADLINE
+static void noop_int_fn(int unused) { }
+static void noop_void_fn(void) { }
+#endif
 
-/* just in case you're ever in an airplane and discover you
-   forgot to install readline-dev. :) */
-int init_input()
+/*
+ * just in case you're ever in an airplane and discover you
+ * forgot to install readline-dev. :)
+ */
+static int init_input(void)
 {
-        int   interactive = isatty (fileno (stdin));
+       int interactive = isatty(fileno(stdin));
 
 #ifdef HAVE_LIBREADLINE
-        using_history();
-        stifle_history(HISTORY);
+       using_history();
+       stifle_history(HISTORY);
 
-        if (!interactive)
-        {
-                rl_prep_term_function = (rl_vintfunc_t *)noop_fn;
-                rl_deprep_term_function = (rl_voidfunc_t *)noop_fn;
-        }
+       if (!interactive) {
+               rl_prep_term_function = noop_int_fn;
+               rl_deprep_term_function = noop_void_fn;
+       }
 
-        rl_attempted_completion_function = (CPPFunction *)command_completion;
-        rl_completion_entry_function = (void *)command_generator;
+       rl_attempted_completion_function = command_completion;
+       rl_completion_entry_function = command_generator;
 #endif
-        return interactive;
+       return interactive;
 }
 
 #ifndef HAVE_LIBREADLINE
 #define add_history(s)
-char * readline(char * prompt)
+static char *readline(char *prompt)
 {
-        int size = 2048;
-        char *line = malloc(size);
-        char *ptr = line;
-        int c;
-        int eof = 0;
-
-        if (line == NULL)
-                return NULL;
-        if (prompt)
-                printf ("%s", prompt);
-
-        while (1) {
-                if ((c = fgetc(stdin)) != EOF) {
-                        if (c == '\n')
-                                goto out;
-                        *ptr++ = (char)c;
-
-                        if (ptr - line >= size - 1) {
-                                char *tmp;
-
-                                size *= 2;
-                                tmp = malloc(size);
-                                if (tmp == NULL)
-                                        goto outfree;
-                                memcpy(tmp, line, ptr - line);
-                                ptr = tmp + (ptr - line);
-                                free(line);
-                                line = tmp;
-                        }
-                } else {
-                        eof = 1;
-                        if (ferror(stdin) || feof(stdin))
-                                goto outfree;
-                        goto out;
-                }
-        }
+       int size = 2048;
+       char *line = malloc(size);
+       char *ptr = line;
+       int c;
+       int eof = 0;
+
+       if (!line)
+               return NULL;
+       if (prompt)
+               printf("%s", prompt);
+
+       while (1) {
+               if ((c = fgetc(stdin)) != EOF) {
+                       if (c == '\n')
+                               goto out;
+                       *ptr++ = (char)c;
+
+                       if (ptr - line >= size - 1) {
+                               char *tmp;
+
+                               size *= 2;
+                               tmp = malloc(size);
+                               if (!tmp)
+                                       goto outfree;
+                               memcpy(tmp, line, ptr - line);
+                               ptr = tmp + (ptr - line);
+                               free(line);
+                               line = tmp;
+                       }
+               } else {
+                       eof = 1;
+                       if (ferror(stdin) || feof(stdin))
+                               goto outfree;
+                       goto out;
+               }
+       }
 out:
-        *ptr = 0;
-        if (eof && (strlen(line) == 0)) {
-                free(line);
-                line = NULL;
-        }
-        return line;
+       *ptr = 0;
+       if (eof && (strlen(line) == 0)) {
+               free(line);
+               line = NULL;
+       }
+       return line;
 outfree:
-        free(line);
-        return NULL;
+       free(line);
+       return NULL;
 }
 #endif
 
 /* this is the command execution machine */
 int Parser_commands(void)
 {
-        char *line, *s;
-        int rc = 0, save_error = 0;
-        int interactive;
-
-        interactive = init_input();
-
-        while(!done) {
-                line = readline(interactive ? parser_prompt : NULL);
-
-                if (!line) break;
-
-                s = skipwhitespace(line);
-
-                if (*s) {
-                        add_history(s);
-                        rc = execute_line(s);
-                }
-                /* stop on error if not-interactive */
-                if (rc != 0 && !interactive) {
-                        if (save_error == 0)
-                                save_error = rc;
-                        if (!ignore_errors)
-                                done = 1;
-                }
-
-                free(line);
-        }
-        if (save_error)
-                rc = save_error;
-        return rc;
+       char *line, *s;
+       int rc = 0, save_error = 0;
+       int interactive;
+
+       interactive = init_input();
+
+       while (!done) {
+               line = readline(interactive ? parser_prompt : NULL);
+
+               if (!line)
+                       break;
+
+               s = skipwhitespace(line);
+
+               if (*s) {
+                       add_history(s);
+                       rc = execute_line(s);
+               }
+               /* stop on error if not-interactive */
+               if (rc != 0 && !interactive) {
+                       if (save_error == 0)
+                               save_error = rc;
+                       if (!ignore_errors)
+                               done = 1;
+               }
+               free(line);
+       }
+
+       if (save_error)
+               rc = save_error;
+
+       return rc;
 }
 
-
 /* sets the parser prompt */
-void Parser_init(char * prompt, command_t * cmds)
+void Parser_init(char *prompt, command_t *cmds)
 {
-        done = 0;
-        top_level = cmds;
-        if (parser_prompt) free(parser_prompt);
-        parser_prompt = strdup(prompt);
+       done = 0;
+       top_level = cmds;
+       if (parser_prompt)
+               free(parser_prompt);
+       parser_prompt = strdup(prompt);
 }
 
 /* frees the parser prompt */
 void Parser_exit(int argc, char *argv[])
 {
-        done = 1;
-        free(parser_prompt);
-        parser_prompt = NULL;
+       done = 1;
+       free(parser_prompt);
+       parser_prompt = NULL;
 }
 
 /* convert a string to an integer */
 int Parser_int(char *s, int *val)
 {
-        int ret;
-
-        if (*s != '0')
-                ret = sscanf(s, "%d", val);
-        else if (*(s+1) != 'x')
-                ret = sscanf(s, "%o", val);
-        else {
-                s++;
-                ret = sscanf(++s, "%x", val);
-        }
-
-        return(ret);
+       int ret;
+
+       if (*s != '0') {
+               ret = sscanf(s, "%d", val);
+       } else if (*(s + 1) != 'x') {
+               ret = sscanf(s, "%o", val);
+       } else {
+               s++;
+               ret = sscanf(++s, "%x", val);
+       }
+
+       return ret;
 }
 
+void Parser_qhelp(int argc, char *argv[])
+{
+       printf("usage: %s [COMMAND] [OPTIONS]... [ARGS]\n",
+              program_invocation_short_name);
+       printf("Without any parameters, interactive mode is invoked\n");
 
-void Parser_qhelp(int argc, char *argv[]) {
-
-        printf("Available commands are:\n");
-
-        print_commands(NULL, top_level);
-        printf("For more help type: help command-name\n");
+       printf("Try '%s help <COMMAND>', or '%s --list-commands' for a list of commands.\n",
+               program_invocation_short_name, program_invocation_short_name);
 }
 
 int Parser_help(int argc, char **argv)
 {
-        char line[1024];
-        char *next, *prev, *tmp;
-        command_t *result, *ambig;
-        int i;
-
-        if ( argc == 1 ) {
-                Parser_qhelp(argc, argv);
-                return 0;
-        }
-
-        line[0]='\0';
-        for ( i = 1 ;  i < argc ; i++ ) {
-                strcat(line, argv[i]);
-        }
-
-        switch ( process(line, &next, top_level, &result, &prev) ) {
-        case CMD_COMPLETE:
-                fprintf(stderr, "%s: %s\n",line, result->pc_help);
-                break;
-        case CMD_NONE:
-                fprintf(stderr, "%s: Unknown command.\n", line);
-                break;
-        case CMD_INCOMPLETE:
-                fprintf(stderr,
-                        "'%s' incomplete command.  Use '%s x' where x is one of:\n",
-                        line, line);
-                fprintf(stderr, "\t");
-                for (i = 0; result->pc_sub_cmd[i].pc_name; i++) {
-                        fprintf(stderr, "%s ", result->pc_sub_cmd[i].pc_name);
-                }
-                fprintf(stderr, "\n");
-                break;
-        case CMD_AMBIG:
-                fprintf(stderr, "Ambiguous command \'%s\'\nOptions: ", line);
-                while( (ambig = find_cmd(prev, result, &tmp)) ) {
-                        fprintf(stderr, "%s ", ambig->pc_name);
-                        result = ambig + 1;
-                }
-                fprintf(stderr, "\n");
-                break;
-        }
-        return 0;
+       char line[1024];
+       char *next, *prev, *tmp;
+       command_t *result, *ambig;
+       int i;
+
+       if (argc == 1) {
+               Parser_qhelp(argc, argv);
+               return 0;
+       }
+
+       /*
+        * Joining command line arguments without space is not critical here
+        * because of this string is used for search a help topic and assume
+        * that only one argument will be (the name of topic). For example:
+        * lst > help ping run
+        * pingrun: Unknown command.
+        */
+       line[0] = '\0';
+       for (i = 1;  i < argc; i++) {
+               if (strlen(argv[i]) >= sizeof(line) - strlen(line))
+                       return -E2BIG;
+               /*
+                * The function strlcat() cannot be used here because of
+                * this function is used in LNet utils that is not linked
+                * with libcfs.a.
+                */
+               strncat(line, argv[i], sizeof(line) - strlen(line));
+       }
+
+       switch (process(line, &next, top_level, &result, &prev)) {
+       case CMD_COMPLETE:
+               fprintf(stderr, "%s: %s\n", line, result->pc_help);
+               break;
+       case CMD_NONE:
+               fprintf(stderr, "%s: Unknown command.\n", line);
+               break;
+       case CMD_INCOMPLETE:
+               fprintf(stderr,
+                       "'%s' incomplete command.  Use '%s x' where x is one of:\n",
+                       line, line);
+               fprintf(stderr, "\t");
+               for (i = 0; result->pc_sub_cmd[i].pc_name; i++)
+                       fprintf(stderr, "%s ", result->pc_sub_cmd[i].pc_name);
+               fprintf(stderr, "\n");
+               break;
+       case CMD_AMBIG:
+               fprintf(stderr, "Ambiguous command \'%s\'\nOptions: ", line);
+               while ((ambig = find_cmd(prev, result, &tmp))) {
+                       fprintf(stderr, "%s ", ambig->pc_name);
+                       result = ambig + 1;
+               }
+               fprintf(stderr, "\n");
+               break;
+       }
+       return 0;
 }
 
-
 void Parser_printhelp(char *cmd)
 {
-        char *argv[] = { "help", cmd };
-        Parser_help(2, argv);
+       char *argv[] = { "help", cmd };
+
+       Parser_help(2, argv);
 }
 
+/* COMMANDS */
 
-/*************************************************************************
- * COMMANDS                                                              *
- *************************************************************************/
-static void print_commands(char * str, command_t * table) {
-        command_t * cmds;
-        char         buf[80];
-
-        for (cmds = table; cmds->pc_name; cmds++) {
-                if (cmds->pc_func) {
-                        if (str) printf("\t%s %s\n", str, cmds->pc_name);
-                        else printf("\t%s\n", cmds->pc_name);
-                }
-                if (cmds->pc_sub_cmd) {
-                        if (str) {
-                                sprintf(buf, "%s %s", str, cmds->pc_name);
-                                print_commands(buf, cmds->pc_sub_cmd);
-                        } else {
-                                print_commands(cmds->pc_name, cmds->pc_sub_cmd);
-                        }
-                }
-        }
+/**
+ * Parser_list_commands() - Output a list of the supported commands.
+ * @cmdlist:     Array of structures describing the commands.
+ * @buffer:      String buffer used to temporarily store the output text.
+ * @buf_size:    Length of the string buffer.
+ * @parent_cmd:          When called recursively, contains the name of the parent cmd.
+ * @col_start:   Column where printing should begin.
+ * @col_num:     The number of commands printed in a single row.
+ *
+ * The commands and subcommands supported by the utility are printed, arranged
+ * into several columns for readability.  If a command supports subcommands, the
+ * function is called recursively, and the name of the parent command is
+ * supplied so that it can be prepended to the names of the subcommands.
+ *
+ * Return: The number of items that were printed.
+ */
+int Parser_list_commands(const command_t *cmdlist, char *buffer,
+                        size_t buf_size, const char *parent_cmd,
+                        int col_start, int col_num)
+{
+       int col = col_start;
+       int char_max;
+       int len;
+       int count = 0;
+       int rc;
+
+       if (col_start >= col_num)
+               return 0;
+
+       char_max = (buf_size - 1) / col_num; /* Reserve 1 char for NUL */
+
+       for (; cmdlist->pc_name; cmdlist++) {
+               if (!cmdlist->pc_func && !cmdlist->pc_sub_cmd)
+                       break;
+               count++;
+               if (parent_cmd)
+                       len = snprintf(&buffer[col * char_max],
+                                      char_max + 1, "%s %s", parent_cmd,
+                                      cmdlist->pc_name);
+               else
+                       len = snprintf(&buffer[col * char_max],
+                                      char_max + 1, "%s", cmdlist->pc_name);
+
+               /* Add trailing spaces to pad the entry to the column size */
+               if (len < char_max) {
+                       snprintf(&buffer[col * char_max] + len,
+                                char_max - len + 1, "%*s", char_max - len,
+                                " ");
+               } else {
+                       buffer[(col + 1) * char_max - 1] = ' ';
+               }
+
+               col++;
+               if (col >= col_num) {
+                       fprintf(stdout, "%s\n", buffer);
+                       col = 0;
+                       buffer[0] = '\0';
+               }
+
+               if (cmdlist->pc_sub_cmd) {
+                       rc = Parser_list_commands(cmdlist->pc_sub_cmd, buffer,
+                                                 buf_size, cmdlist->pc_name,
+                                                 col, col_num);
+                       col = (col + rc) % col_num;
+                       count += rc;
+               }
+       }
+       if (!parent_cmd && col != 0)
+               fprintf(stdout, "%s\n", buffer);
+       return count;
 }
 
 char *Parser_getstr(const char *prompt, const char *deft, char *res,
-                    size_t len)
+                   size_t len)
 {
-        char *line = NULL;
-        int size = strlen(prompt) + strlen(deft) + 8;
-        char *theprompt;
-        theprompt = malloc(size);
-        assert(theprompt);
-
-        sprintf(theprompt, "%s [%s]: ", prompt, deft);
-
-        line  = readline(theprompt);
-        free(theprompt);
-
-        if ( line == NULL || *line == '\0' ) {
-                strncpy(res, deft, len);
-        } else {
-                strncpy(res, line, len);
-        }
-
-        if ( line ) {
-                free(line);
-                return res;
-        } else {
-                return NULL;
-        }
+       char *line = NULL;
+       int size = strlen(prompt) + strlen(deft) + 8;
+       char *theprompt;
+
+       theprompt = malloc(size);
+       assert(theprompt);
+
+       snprintf(theprompt, size, "%s [%s]: ", prompt, deft);
+
+       line  = readline(theprompt);
+       free(theprompt);
+
+       /*
+        * The function strlcpy() cannot be used here because of
+        * this function is used in LNet utils that is not linked
+        * with libcfs.a.
+        */
+       if (!line || *line == '\0')
+               strncpy(res, deft, len);
+       else
+               strncpy(res, line, len);
+       res[len - 1] = '\0';
+
+       if (line) {
+               free(line);
+               return res;
+       }
+       return NULL;
 }
 
 /* get integer from prompt, loop forever to get it */
 int Parser_getint(const char *prompt, long min, long max, long deft, int base)
 {
-        int rc;
-        long result;
-        char *line;
-        int size = strlen(prompt) + 40;
-        char *theprompt = malloc(size);
-        assert(theprompt);
-        sprintf(theprompt,"%s [%ld, (0x%lx)]: ", prompt, deft, deft);
-
-        fflush(stdout);
-
-        do {
-                line = NULL;
-                line = readline(theprompt);
-                if ( !line ) {
-                        fprintf(stdout, "Please enter an integer.\n");
-                        fflush(stdout);
-                        continue;
-                }
-                if ( *line == '\0' ) {
-                        free(line);
-                        result =  deft;
-                        break;
-                }
-                rc = Parser_arg2int(line, &result, base);
-                free(line);
-                if ( rc != 0 ) {
-                        fprintf(stdout, "Invalid string.\n");
-                        fflush(stdout);
-                } else if ( result > max || result < min ) {
-                        fprintf(stdout, "Error: response must lie between %ld and %ld.\n",
-                                min, max);
-                        fflush(stdout);
-                } else {
-                        break;
-                }
-        } while ( 1 ) ;
-
-        if (theprompt)
-                free(theprompt);
-        return result;
-
+       int rc;
+       long result;
+       char *line;
+       int size = strlen(prompt) + 40;
+       char *theprompt = malloc(size);
+
+       assert(theprompt);
+       snprintf(theprompt, size, "%s [%ld, (0x%lx)]: ", prompt, deft, deft);
+       fflush(stdout);
+
+       do {
+               line = NULL;
+               line = readline(theprompt);
+               if (!line) {
+                       fprintf(stdout, "Please enter an integer.\n");
+                       fflush(stdout);
+                       continue;
+               }
+               if (*line == '\0') {
+                       free(line);
+                       result =  deft;
+                       break;
+               }
+               rc = Parser_arg2int(line, &result, base);
+               free(line);
+               if (rc != 0) {
+                       fprintf(stdout, "Invalid string.\n");
+                       fflush(stdout);
+               } else if (result > max || result < min) {
+                       fprintf(stdout,
+                               "Error: response must lie between %ld and %ld.\n",
+                               min, max);
+                       fflush(stdout);
+               } else {
+                       break;
+               }
+       } while (1);
+
+       if (theprompt)
+               free(theprompt);
+       return result;
 }
 
 /* get boolean (starting with YyNn; loop forever */
 int Parser_getbool(const char *prompt, int deft)
 {
-        int result = 0;
-        char *line;
-        int size = strlen(prompt) + 8;
-        char *theprompt = malloc(size);
-        assert(theprompt);
-
-        fflush(stdout);
-
-        if ( deft != 0 && deft != 1 ) {
-                fprintf(stderr, "Error: Parser_getbool given bad default %d\n",
-                        deft);
-                assert ( 0 );
-        }
-        sprintf(theprompt, "%s [%s]: ", prompt, (deft==0)? "N" : "Y");
-
-        do {
-                line = NULL;
-                line = readline(theprompt);
-                if ( line == NULL ) {
-                        result = deft;
-                        break;
-                }
-                if ( *line == '\0' ) {
-                        result = deft;
-                        break;
-                }
-                if ( *line == 'y' || *line == 'Y' ) {
-                        result = 1;
-                        break;
-                }
-                if ( *line == 'n' || *line == 'N' ) {
-                        result = 0;
-                        break;
-                }
-                if ( line )
-                        free(line);
-                fprintf(stdout, "Invalid string. Must start with yY or nN\n");
-                fflush(stdout);
-        } while ( 1 );
-
-        if ( line )
-                free(line);
-        if ( theprompt )
-                free(theprompt);
-        return result;
+       int result = 0;
+       char *line;
+       int size = strlen(prompt) + 8;
+       char *theprompt = malloc(size);
+
+       assert(theprompt);
+       fflush(stdout);
+
+       if (deft != 0 && deft != 1) {
+               fprintf(stderr, "Error: Parser_getbool given bad default %d\n",
+                       deft);
+               assert(0);
+       }
+       snprintf(theprompt, size, "%s [%s]: ", prompt, (deft == 0) ? "N" : "Y");
+
+       do {
+               line = NULL;
+               line = readline(theprompt);
+               if (!line) {
+                       result = deft;
+                       break;
+               }
+               if (*line == '\0') {
+                       result = deft;
+                       break;
+               }
+               if (*line == 'y' || *line == 'Y') {
+                       result = 1;
+                       break;
+               }
+               if (*line == 'n' || *line == 'N') {
+                       result = 0;
+                       break;
+               }
+               if (line)
+                       free(line);
+               fprintf(stdout, "Invalid string. Must start with yY or nN\n");
+               fflush(stdout);
+       } while (1);
+
+       if (line)
+               free(line);
+       if (theprompt)
+               free(theprompt);
+
+       return result;
 }
 
 /* parse int out of a string or prompt for it */
 long Parser_intarg(const char *inp, const char *prompt, int deft,
-                   int min, int max, int base)
+                  int min, int max, int base)
 {
-        long result;
-        int rc;
-
-        rc = Parser_arg2int(inp, &result, base);
-
-        if ( rc == 0 ) {
-                return result;
-        } else {
-                return Parser_getint(prompt, deft, min, max, base);
-        }
+       long result;
+       int rc;
+
+       rc = Parser_arg2int(inp, &result, base);
+       if (rc == 0)
+               return result;
+       else
+               return Parser_getint(prompt, deft, min, max, base);
 }
 
 /* parse int out of a string or prompt for it */
 char *Parser_strarg(char *inp, const char *prompt, const char *deft,
-                    char *answer, int len)
+                   char *answer, int len)
 {
-        if ( inp == NULL || *inp == '\0' ) {
-                return Parser_getstr(prompt, deft, answer, len);
-        } else
-                return inp;
+       if (!inp || *inp == '\0')
+               return Parser_getstr(prompt, deft, answer, len);
+       else
+               return inp;
 }
 
-/* change a string into a number: return 0 on success. No invalid characters
-   allowed. The processing of base and validity follows strtol(3)*/
+/*
+ * change a string into a number: return 0 on success. No invalid characters
+ * allowed. The processing of base and validity follows strtol(3)
+ */
 int Parser_arg2int(const char *inp, long *result, int base)
 {
-        char *endptr;
+       char *endptr;
 
-        if ( (base !=0) && (base < 2 || base > 36) )
-                return 1;
+       if ((base != 0) && (base < 2 || base > 36))
+               return 1;
 
-        *result = strtol(inp, &endptr, base);
+       *result = strtol(inp, &endptr, base);
 
-        if ( *inp != '\0' && *endptr == '\0' )
-                return 0;
-        else
-                return 1;
+       if (*inp != '\0' && *endptr == '\0')
+               return 0;
+       else
+               return 1;
 }
 
 /* Convert human readable size string to and int; "1k" -> 1000 */
-int Parser_size (int *sizep, char *str) {
-        int size;
-        char mod[32];
-
-        switch (sscanf (str, "%d%1[gGmMkK]", &size, mod)) {
-        default:
-                return (-1);
-
-        case 1:
-                *sizep = size;
-                return (0);
-
-        case 2:
-                switch (*mod) {
-                case 'g':
-                case 'G':
-                        *sizep = size << 30;
-                        return (0);
-
-                case 'm':
-                case 'M':
-                        *sizep = size << 20;
-                        return (0);
-
-                case 'k':
-                case 'K':
-                        *sizep = size << 10;
-                        return (0);
-
-                default:
-                        *sizep = size;
-                        return (0);
-                }
-        }
+int Parser_size(unsigned long *sizep, char *str)
+{
+       unsigned long size;
+       char mod[32];
+
+       switch (sscanf(str, "%lu%1[gGmMkK]", &size, mod)) {
+       default:
+               return -1;
+       case 1:
+               *sizep = size;
+               return 0;
+       case 2:
+               switch (*mod) {
+               case 'g':
+               case 'G':
+                       *sizep = size << 30;
+                       return 0;
+               case 'm':
+               case 'M':
+                       *sizep = size << 20;
+                       return 0;
+               case 'k':
+               case 'K':
+                       *sizep = size << 10;
+                       return 0;
+               default:
+                       *sizep = size;
+                       return 0;
+               }
+       }
 }
 
 /* Convert a string boolean to an int; "enable" -> 1 */
-int Parser_bool (int *b, char *str) {
-        if (!strcasecmp (str, "no") ||
-            !strcasecmp (str, "n") ||
-            !strcasecmp (str, "off") ||
-            !strcasecmp (str, "down") ||
-            !strcasecmp (str, "disable"))
-        {
-                *b = 0;
-                return (0);
-        }
-
-        if (!strcasecmp (str, "yes") ||
-            !strcasecmp (str, "y") ||
-            !strcasecmp (str, "on") ||
-            !strcasecmp (str, "up") ||
-            !strcasecmp (str, "enable"))
-        {
-                *b = 1;
-                return (0);
-        }
-
-        return (-1);
+int Parser_bool(int *b, char *str)
+{
+       if (!strcasecmp(str, "no") || !strcasecmp(str, "n") ||
+           !strcasecmp(str, "off") || !strcasecmp(str, "down") ||
+           !strcasecmp(str, "disable")) {
+               *b = 0;
+               return 0;
+       }
+
+       if (!strcasecmp(str, "yes") || !strcasecmp(str, "y") ||
+           !strcasecmp(str, "on") || !strcasecmp(str, "up") ||
+           !strcasecmp(str, "enable")) {
+               *b = 1;
+               return 0;
+       }
+
+       return -1;
 }
 
 int Parser_quit(int argc, char **argv)
 {
-        argc = argc;
-        argv = argv;
-        done = 1;
-        return 0;
+       argc = argc;
+       argv = argv;
+       done = 1;
+       return 0;
+}
+
+int Parser_version(int argc, char **argv)
+{
+       fprintf(stdout, "%s %s\n", program_invocation_short_name,
+               LUSTRE_VERSION_STRING);
+       return 0;
 }