Free Electrons

Embedded Linux Experts

  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
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
/*
 * builtin-help.c
 *
 * Builtin help command
 */
#include "perf.h"
#include "util/cache.h"
#include "builtin.h"
#include "util/exec_cmd.h"
#include "common-cmds.h"
#include "util/parse-options.h"
#include "util/run-command.h"
#include "util/help.h"
#include "util/debug.h"

static struct man_viewer_list {
	struct man_viewer_list *next;
	char name[FLEX_ARRAY];
} *man_viewer_list;

static struct man_viewer_info_list {
	struct man_viewer_info_list *next;
	const char *info;
	char name[FLEX_ARRAY];
} *man_viewer_info_list;

enum help_format {
	HELP_FORMAT_NONE,
	HELP_FORMAT_MAN,
	HELP_FORMAT_INFO,
	HELP_FORMAT_WEB,
};

static enum help_format parse_help_format(const char *format)
{
	if (!strcmp(format, "man"))
		return HELP_FORMAT_MAN;
	if (!strcmp(format, "info"))
		return HELP_FORMAT_INFO;
	if (!strcmp(format, "web") || !strcmp(format, "html"))
		return HELP_FORMAT_WEB;

	pr_err("unrecognized help format '%s'", format);
	return HELP_FORMAT_NONE;
}

static const char *get_man_viewer_info(const char *name)
{
	struct man_viewer_info_list *viewer;

	for (viewer = man_viewer_info_list; viewer; viewer = viewer->next) {
		if (!strcasecmp(name, viewer->name))
			return viewer->info;
	}
	return NULL;
}

static int check_emacsclient_version(void)
{
	struct strbuf buffer = STRBUF_INIT;
	struct child_process ec_process;
	const char *argv_ec[] = { "emacsclient", "--version", NULL };
	int version;

	/* emacsclient prints its version number on stderr */
	memset(&ec_process, 0, sizeof(ec_process));
	ec_process.argv = argv_ec;
	ec_process.err = -1;
	ec_process.stdout_to_stderr = 1;
	if (start_command(&ec_process)) {
		fprintf(stderr, "Failed to start emacsclient.\n");
		return -1;
	}
	strbuf_read(&buffer, ec_process.err, 20);
	close(ec_process.err);

	/*
	 * Don't bother checking return value, because "emacsclient --version"
	 * seems to always exits with code 1.
	 */
	finish_command(&ec_process);

	if (prefixcmp(buffer.buf, "emacsclient")) {
		fprintf(stderr, "Failed to parse emacsclient version.\n");
		strbuf_release(&buffer);
		return -1;
	}

	strbuf_remove(&buffer, 0, strlen("emacsclient"));
	version = atoi(buffer.buf);

	if (version < 22) {
		fprintf(stderr,
			"emacsclient version '%d' too old (< 22).\n",
			version);
		strbuf_release(&buffer);
		return -1;
	}

	strbuf_release(&buffer);
	return 0;
}

static void exec_woman_emacs(const char *path, const char *page)
{
	if (!check_emacsclient_version()) {
		/* This works only with emacsclient version >= 22. */
		struct strbuf man_page = STRBUF_INIT;

		if (!path)
			path = "emacsclient";
		strbuf_addf(&man_page, "(woman \"%s\")", page);
		execlp(path, "emacsclient", "-e", man_page.buf, NULL);
		warning("failed to exec '%s': %s", path, strerror(errno));
	}
}

static void exec_man_konqueror(const char *path, const char *page)
{
	const char *display = getenv("DISPLAY");
	if (display && *display) {
		struct strbuf man_page = STRBUF_INIT;
		const char *filename = "kfmclient";

		/* It's simpler to launch konqueror using kfmclient. */
		if (path) {
			const char *file = strrchr(path, '/');
			if (file && !strcmp(file + 1, "konqueror")) {
				char *new = strdup(path);
				char *dest = strrchr(new, '/');

				/* strlen("konqueror") == strlen("kfmclient") */
				strcpy(dest + 1, "kfmclient");
				path = new;
			}
			if (file)
				filename = file;
		} else
			path = "kfmclient";
		strbuf_addf(&man_page, "man:%s(1)", page);
		execlp(path, filename, "newTab", man_page.buf, NULL);
		warning("failed to exec '%s': %s", path, strerror(errno));
	}
}

static void exec_man_man(const char *path, const char *page)
{
	if (!path)
		path = "man";
	execlp(path, "man", page, NULL);
	warning("failed to exec '%s': %s", path, strerror(errno));
}

static void exec_man_cmd(const char *cmd, const char *page)
{
	struct strbuf shell_cmd = STRBUF_INIT;
	strbuf_addf(&shell_cmd, "%s %s", cmd, page);
	execl("/bin/sh", "sh", "-c", shell_cmd.buf, NULL);
	warning("failed to exec '%s': %s", cmd, strerror(errno));
}

static void add_man_viewer(const char *name)
{
	struct man_viewer_list **p = &man_viewer_list;
	size_t len = strlen(name);

	while (*p)
		p = &((*p)->next);
	*p = zalloc(sizeof(**p) + len + 1);
	strncpy((*p)->name, name, len);
}

static int supported_man_viewer(const char *name, size_t len)
{
	return (!strncasecmp("man", name, len) ||
		!strncasecmp("woman", name, len) ||
		!strncasecmp("konqueror", name, len));
}

static void do_add_man_viewer_info(const char *name,
				   size_t len,
				   const char *value)
{
	struct man_viewer_info_list *new = zalloc(sizeof(*new) + len + 1);

	strncpy(new->name, name, len);
	new->info = strdup(value);
	new->next = man_viewer_info_list;
	man_viewer_info_list = new;
}

static int add_man_viewer_path(const char *name,
			       size_t len,
			       const char *value)
{
	if (supported_man_viewer(name, len))
		do_add_man_viewer_info(name, len, value);
	else
		warning("'%s': path for unsupported man viewer.\n"
			"Please consider using 'man.<tool>.cmd' instead.",
			name);

	return 0;
}

static int add_man_viewer_cmd(const char *name,
			      size_t len,
			      const char *value)
{
	if (supported_man_viewer(name, len))
		warning("'%s': cmd for supported man viewer.\n"
			"Please consider using 'man.<tool>.path' instead.",
			name);
	else
		do_add_man_viewer_info(name, len, value);

	return 0;
}

static int add_man_viewer_info(const char *var, const char *value)
{
	const char *name = var + 4;
	const char *subkey = strrchr(name, '.');

	if (!subkey)
		return error("Config with no key for man viewer: %s", name);

	if (!strcmp(subkey, ".path")) {
		if (!value)
			return config_error_nonbool(var);
		return add_man_viewer_path(name, subkey - name, value);
	}
	if (!strcmp(subkey, ".cmd")) {
		if (!value)
			return config_error_nonbool(var);
		return add_man_viewer_cmd(name, subkey - name, value);
	}

	warning("'%s': unsupported man viewer sub key.", subkey);
	return 0;
}

static int perf_help_config(const char *var, const char *value, void *cb)
{
	enum help_format *help_formatp = cb;

	if (!strcmp(var, "help.format")) {
		if (!value)
			return config_error_nonbool(var);
		*help_formatp = parse_help_format(value);
		if (*help_formatp == HELP_FORMAT_NONE)
			return -1;
		return 0;
	}
	if (!strcmp(var, "man.viewer")) {
		if (!value)
			return config_error_nonbool(var);
		add_man_viewer(value);
		return 0;
	}
	if (!prefixcmp(var, "man."))
		return add_man_viewer_info(var, value);

	return perf_default_config(var, value, cb);
}

static struct cmdnames main_cmds, other_cmds;

void list_common_cmds_help(void)
{
	unsigned int i, longest = 0;

	for (i = 0; i < ARRAY_SIZE(common_cmds); i++) {
		if (longest < strlen(common_cmds[i].name))
			longest = strlen(common_cmds[i].name);
	}

	puts(" The most commonly used perf commands are:");
	for (i = 0; i < ARRAY_SIZE(common_cmds); i++) {
		printf("   %-*s   ", longest, common_cmds[i].name);
		puts(common_cmds[i].help);
	}
}

static int is_perf_command(const char *s)
{
	return is_in_cmdlist(&main_cmds, s) ||
		is_in_cmdlist(&other_cmds, s);
}

static const char *prepend(const char *prefix, const char *cmd)
{
	size_t pre_len = strlen(prefix);
	size_t cmd_len = strlen(cmd);
	char *p = malloc(pre_len + cmd_len + 1);
	memcpy(p, prefix, pre_len);
	strcpy(p + pre_len, cmd);
	return p;
}

static const char *cmd_to_page(const char *perf_cmd)
{
	if (!perf_cmd)
		return "perf";
	else if (!prefixcmp(perf_cmd, "perf"))
		return perf_cmd;
	else
		return prepend("perf-", perf_cmd);
}

static void setup_man_path(void)
{
	struct strbuf new_path = STRBUF_INIT;
	const char *old_path = getenv("MANPATH");

	/* We should always put ':' after our path. If there is no
	 * old_path, the ':' at the end will let 'man' to try
	 * system-wide paths after ours to find the manual page. If
	 * there is old_path, we need ':' as delimiter. */
	strbuf_addstr(&new_path, system_path(PERF_MAN_PATH));
	strbuf_addch(&new_path, ':');
	if (old_path)
		strbuf_addstr(&new_path, old_path);

	setenv("MANPATH", new_path.buf, 1);

	strbuf_release(&new_path);
}

static void exec_viewer(const char *name, const char *page)
{
	const char *info = get_man_viewer_info(name);

	if (!strcasecmp(name, "man"))
		exec_man_man(info, page);
	else if (!strcasecmp(name, "woman"))
		exec_woman_emacs(info, page);
	else if (!strcasecmp(name, "konqueror"))
		exec_man_konqueror(info, page);
	else if (info)
		exec_man_cmd(info, page);
	else
		warning("'%s': unknown man viewer.", name);
}

static int show_man_page(const char *perf_cmd)
{
	struct man_viewer_list *viewer;
	const char *page = cmd_to_page(perf_cmd);
	const char *fallback = getenv("PERF_MAN_VIEWER");

	setup_man_path();
	for (viewer = man_viewer_list; viewer; viewer = viewer->next)
		exec_viewer(viewer->name, page); /* will return when unable */

	if (fallback)
		exec_viewer(fallback, page);
	exec_viewer("man", page);

	pr_err("no man viewer handled the request");
	return -1;
}

static int show_info_page(const char *perf_cmd)
{
	const char *page = cmd_to_page(perf_cmd);
	setenv("INFOPATH", system_path(PERF_INFO_PATH), 1);
	execlp("info", "info", "perfman", page, NULL);
	return -1;
}

static int get_html_page_path(struct strbuf *page_path, const char *page)
{
	struct stat st;
	const char *html_path = system_path(PERF_HTML_PATH);

	/* Check that we have a perf documentation directory. */
	if (stat(mkpath("%s/perf.html", html_path), &st)
	    || !S_ISREG(st.st_mode)) {
		pr_err("'%s': not a documentation directory.", html_path);
		return -1;
	}

	strbuf_init(page_path, 0);
	strbuf_addf(page_path, "%s/%s.html", html_path, page);

	return 0;
}

/*
 * If open_html is not defined in a platform-specific way (see for
 * example compat/mingw.h), we use the script web--browse to display
 * HTML.
 */
#ifndef open_html
static void open_html(const char *path)
{
	execl_perf_cmd("web--browse", "-c", "help.browser", path, NULL);
}
#endif

static int show_html_page(const char *perf_cmd)
{
	const char *page = cmd_to_page(perf_cmd);
	struct strbuf page_path; /* it leaks but we exec bellow */

	if (get_html_page_path(&page_path, page) != 0)
		return -1;

	open_html(page_path.buf);

	return 0;
}

int cmd_help(int argc, const char **argv, const char *prefix __maybe_unused)
{
	bool show_all = false;
	enum help_format help_format = HELP_FORMAT_MAN;
	struct option builtin_help_options[] = {
	OPT_BOOLEAN('a', "all", &show_all, "print all available commands"),
	OPT_SET_UINT('m', "man", &help_format, "show man page", HELP_FORMAT_MAN),
	OPT_SET_UINT('w', "web", &help_format, "show manual in web browser",
			HELP_FORMAT_WEB),
	OPT_SET_UINT('i', "info", &help_format, "show info page",
			HELP_FORMAT_INFO),
	OPT_END(),
	};
	const char * const builtin_help_usage[] = {
		"perf help [--all] [--man|--web|--info] [command]",
		NULL
	};
	const char *alias;
	int rc = 0;

	load_command_list("perf-", &main_cmds, &other_cmds);

	perf_config(perf_help_config, &help_format);

	argc = parse_options(argc, argv, builtin_help_options,
			builtin_help_usage, 0);

	if (show_all) {
		printf("\n usage: %s\n\n", perf_usage_string);
		list_commands("perf commands", &main_cmds, &other_cmds);
		printf(" %s\n\n", perf_more_info_string);
		return 0;
	}

	if (!argv[0]) {
		printf("\n usage: %s\n\n", perf_usage_string);
		list_common_cmds_help();
		printf("\n %s\n\n", perf_more_info_string);
		return 0;
	}

	alias = alias_lookup(argv[0]);
	if (alias && !is_perf_command(argv[0])) {
		printf("`perf %s' is aliased to `%s'\n", argv[0], alias);
		return 0;
	}

	switch (help_format) {
	case HELP_FORMAT_MAN:
		rc = show_man_page(argv[0]);
		break;
	case HELP_FORMAT_INFO:
		rc = show_info_page(argv[0]);
		break;
	case HELP_FORMAT_WEB:
		rc = show_html_page(argv[0]);
		break;
	case HELP_FORMAT_NONE:
		/* fall-through */
	default:
		rc = -1;
		break;
	}

	return rc;
}