summaryrefslogtreecommitdiff
path: root/help.c
blob: 311a43202c5043142ebfb00a0f12fa235aac8592 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
/*
 * 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 <limits.h>
#include <getopt.h>

#include "commands.h"
#include "utils.h"
#include "help.h"

#define USAGE_SHORT		1U
#define USAGE_LONG		2U
#define USAGE_OPTIONS		4U
#define USAGE_LISTING		8U

static char argv0_buf[ARGV0_BUF_SIZE] = "btrfs";

const char *get_argv0_buf(void)
{
	return argv0_buf;
}

void fixup_argv0(char **argv, const char *token)
{
	int len = strlen(argv0_buf);

	snprintf(argv0_buf + len, sizeof(argv0_buf) - len, " %s", token);
	argv[0] = argv0_buf;
}

void set_argv0(char **argv)
{
	strncpy(argv0_buf, argv[0], sizeof(argv0_buf));
	argv0_buf[sizeof(argv0_buf) - 1] = 0;
}

int check_argc_exact(int nargs, int expected)
{
	if (nargs < expected)
		fprintf(stderr, "%s: too few arguments\n", argv0_buf);
	if (nargs > expected)
		fprintf(stderr, "%s: too many arguments\n", argv0_buf);

	return nargs != expected;
}

int check_argc_min(int nargs, int expected)
{
	if (nargs < expected) {
		fprintf(stderr, "%s: too few arguments\n", argv0_buf);
		return 1;
	}

	return 0;
}

int check_argc_max(int nargs, int expected)
{
	if (nargs > expected) {
		fprintf(stderr, "%s: too many arguments\n", argv0_buf);
		return 1;
	}

	return 0;
}

/*
 * Preprocess @argv with getopt_long to reorder options and consume the "--"
 * option separator.
 * Unknown short and long options are reported, optionally the @usage is printed
 * before exit.
 */
void clean_args_no_options(int argc, char *argv[], const char * const *usagestr)
{
	static const struct option long_options[] = {
		{NULL, 0, NULL, 0}
	};

	while (1) {
		int c = getopt_long(argc, argv, "", long_options, NULL);

		if (c < 0)
			break;

		switch (c) {
		default:
			if (usagestr)
				usage(usagestr);
		}
	}
}

/*
 * Same as clean_args_no_options but pass through arguments that could look
 * like short options. Eg. reisze which takes a negative resize argument like
 * '-123M' .
 *
 * This accepts only two forms:
 * - "-- option1 option2 ..."
 * - "option1 option2 ..."
 */
void clean_args_no_options_relaxed(int argc, char *argv[], const char * const *usagestr)
{
	if (argc <= 1)
		return;

	if (strcmp(argv[1], "--") == 0)
		optind = 2;
}

static int do_usage_one_command(const char * const *usagestr,
				unsigned int flags, FILE *outf)
{
	int pad = 4;
	const char *prefix = "usage: ";
	const char *pad_listing = "    ";

	if (!usagestr || !*usagestr)
		return -1;

	if (flags & USAGE_LISTING)
		prefix = pad_listing;

	fputs(prefix, outf);
	if (strchr(*usagestr, '\n') == NULL) {
		fputs(*usagestr, outf);
	} else {
		const char *c = *usagestr;
		const char *nprefix = "       ";

		if (flags & USAGE_LISTING)
			nprefix = pad_listing;

		for (c = *usagestr; *c; c++) {
			fputc(*c, outf);
			if (*c == '\n')
				fputs(nprefix, outf);
		}
	}
	usagestr++;

	/* a short one-line description (mandatory) */
	if ((flags & USAGE_SHORT) == 0)
		return 0;
	else if (!*usagestr)
		return -2;
	fputc('\n', outf);

	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,
				  int alias, FILE *outf)
{
	unsigned int flags = 0;
	int ret;

	if (!alias)
		flags |= USAGE_SHORT;
	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, 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);
}

__attribute__((noreturn))
void usage(const char * const *usagestr)
{
	usage_command_usagestr(usagestr, NULL, 1, 1);
	exit(1);
}

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->flags & 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, cmd->flags & CMD_ALIAS, outf);
			if (cmd->flags & CMD_ALIAS)
				putchar('\n');
			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_short(const struct cmd_group *grp)
{
	const char * const *usagestr = grp->usagestr;
	FILE *outf = stdout;
	const struct cmd_struct *cmd;

	if (usagestr && *usagestr) {
		fprintf(outf, "usage: %s\n", *usagestr++);
		while (*usagestr)
			fprintf(outf, "   or: %s\n", *usagestr++);
	}

	fputc('\n', outf);

	fprintf(outf, "Command groups:\n");
	for (cmd = grp->commands; cmd->token; cmd++) {
		if (cmd->flags & CMD_HIDDEN)
			continue;

		if (!cmd->next)
			continue;

		fprintf(outf, "  %-16s  %s\n", cmd->token, cmd->next->infostr);
	}

	fprintf(outf, "\nCommands:\n");
	for (cmd = grp->commands; cmd->token; cmd++) {
		if (cmd->flags & CMD_HIDDEN)
			continue;

		if (cmd->next)
			continue;

		fprintf(outf, "  %-16s  %s\n", cmd->token, cmd->usagestr[1]);
	}

	fputc('\n', outf);
	fprintf(stderr, "For an overview of a given command use 'btrfs command --help'\n");
	fprintf(stderr, "or 'btrfs [command...] --help --full' to print all available options.\n");
	fprintf(stderr, "Any command name can be shortened as far as it stays unambiguous,\n");
	fprintf(stderr, "however it is recommended to use full command names in scripts.\n");
	fprintf(stderr, "All command groups have their manual page named 'btrfs-<group>'.\n");
}

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);
}

__attribute__((noreturn))
void help_unknown_token(const char *arg, const struct cmd_group *grp)
{
	fprintf(stderr, "%s: unknown token '%s'\n", get_argv0_buf(), arg);
	usage_command_group(grp, 0, 1);
	exit(1);
}

__attribute__((noreturn))
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", get_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);
}