btrfs-progs/help.c

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/*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public
* License v2 as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public
* License along with this program; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 021110-1307, USA.
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "commands.h"
extern char argv0_buf[ARGV0_BUF_SIZE];
#define USAGE_SHORT 1U
#define USAGE_LONG 2U
#define USAGE_OPTIONS 4U
#define USAGE_LISTING 8U
static int do_usage_one_command(const char * const *usagestr,
unsigned int flags, FILE *outf)
{
int pad = 4;
if (!usagestr || !*usagestr)
return -1;
fprintf(outf, "%s%s\n", (flags & USAGE_LISTING) ? " " : "usage: ",
*usagestr++);
/* a short one-line description (mandatory) */
if ((flags & USAGE_SHORT) == 0)
return 0;
else if (!*usagestr)
return -2;
if (flags & USAGE_LISTING)
pad = 8;
else
fputc('\n', outf);
fprintf(outf, "%*s%s\n", pad, "", *usagestr++);
/* a long (possibly multi-line) description (optional) */
if (!*usagestr || ((flags & USAGE_LONG) == 0))
return 0;
if (**usagestr)
fputc('\n', outf);
while (*usagestr && **usagestr)
fprintf(outf, "%*s%s\n", pad, "", *usagestr++);
/* options (optional) */
if (!*usagestr || ((flags & USAGE_OPTIONS) == 0))
return 0;
/*
* options (if present) should always (even if there is no long
* description) be prepended with an empty line, skip it
*/
usagestr++;
fputc('\n', outf);
while (*usagestr)
fprintf(outf, "%*s%s\n", pad, "", *usagestr++);
return 0;
}
static int usage_command_internal(const char * const *usagestr,
const char *token, int full, int lst,
FILE *outf)
{
unsigned int flags = USAGE_SHORT;
int ret;
if (full)
flags |= USAGE_LONG | USAGE_OPTIONS;
if (lst)
flags |= USAGE_LISTING;
ret = do_usage_one_command(usagestr, flags, outf);
switch (ret) {
case -1:
fprintf(outf, "No usage for '%s'\n", token);
break;
case -2:
fprintf(outf, "No short description for '%s'\n", token);
break;
}
return ret;
}
static void usage_command_usagestr(const char * const *usagestr,
const char *token, int full, int err)
{
FILE *outf = err ? stderr : stdout;
int ret;
ret = usage_command_internal(usagestr, token, full, 0, outf);
if (!ret)
fputc('\n', outf);
}
void usage_command(const struct cmd_struct *cmd, int full, int err)
{
usage_command_usagestr(cmd->usagestr, cmd->token, full, err);
}
void usage(const char * const *usagestr)
{
usage_command_usagestr(usagestr, NULL, 1, 1);
exit(129);
}
static void usage_command_group_internal(const struct cmd_group *grp, int full,
FILE *outf)
{
const struct cmd_struct *cmd = grp->commands;
int do_sep = 0;
for (; cmd->token; cmd++) {
if (cmd->hidden)
continue;
if (full && cmd != grp->commands)
fputc('\n', outf);
if (!cmd->next) {
if (do_sep) {
fputc('\n', outf);
do_sep = 0;
}
usage_command_internal(cmd->usagestr, cmd->token, full,
1, outf);
continue;
}
/* this is an entry point to a nested command group */
if (!full && cmd != grp->commands)
fputc('\n', outf);
usage_command_group_internal(cmd->next, full, outf);
if (!full)
do_sep = 1;
}
}
void usage_command_group(const struct cmd_group *grp, int full, int err)
{
const char * const *usagestr = grp->usagestr;
FILE *outf = err ? stderr : stdout;
if (usagestr && *usagestr) {
fprintf(outf, "usage: %s\n", *usagestr++);
while (*usagestr)
fprintf(outf, " or: %s\n", *usagestr++);
}
fputc('\n', outf);
usage_command_group_internal(grp, full, outf);
fputc('\n', outf);
if (grp->infostr)
fprintf(outf, "%s\n", grp->infostr);
}
void help_unknown_token(const char *arg, const struct cmd_group *grp)
{
fprintf(stderr, "%s: unknown token '%s'\n", argv0_buf, arg);
usage_command_group(grp, 0, 1);
exit(1);
}
void help_ambiguous_token(const char *arg, const struct cmd_group *grp)
{
const struct cmd_struct *cmd = grp->commands;
fprintf(stderr, "%s: ambiguous token '%s'\n", argv0_buf, arg);
fprintf(stderr, "\nDid you mean one of these ?\n");
for (; cmd->token; cmd++) {
if (!prefixcmp(cmd->token, arg))
fprintf(stderr, "\t%s\n", cmd->token);
}
exit(1);
}
void help_command_group(const struct cmd_group *grp, int argc, char **argv)
{
int full = 0;
if (argc > 1) {
if (!strcmp(argv[1], "--full"))
full = 1;
}
usage_command_group(grp, full, 0);
}