Root/tools/perf/builtin-help.c

Source at commit ec7cab4cbb721bff91ec924ec691efd8daf36579 created 9 years 7 months ago.
By Maarten ter Huurne, MIPS: JZ4740: A320: Updated quickstart documentation.
1/*
2 * builtin-help.c
3 *
4 * Builtin help command
5 */
6#include "perf.h"
7#include "util/cache.h"
8#include "builtin.h"
9#include "util/exec_cmd.h"
10#include "common-cmds.h"
11#include "util/parse-options.h"
12#include "util/run-command.h"
13#include "util/help.h"
14
15static struct man_viewer_list {
16    struct man_viewer_list *next;
17    char name[FLEX_ARRAY];
18} *man_viewer_list;
19
20static struct man_viewer_info_list {
21    struct man_viewer_info_list *next;
22    const char *info;
23    char name[FLEX_ARRAY];
24} *man_viewer_info_list;
25
26enum help_format {
27    HELP_FORMAT_MAN,
28    HELP_FORMAT_INFO,
29    HELP_FORMAT_WEB,
30};
31
32static bool show_all = false;
33static enum help_format help_format = HELP_FORMAT_MAN;
34static struct option builtin_help_options[] = {
35    OPT_BOOLEAN('a', "all", &show_all, "print all available commands"),
36    OPT_SET_UINT('m', "man", &help_format, "show man page", HELP_FORMAT_MAN),
37    OPT_SET_UINT('w', "web", &help_format, "show manual in web browser",
38            HELP_FORMAT_WEB),
39    OPT_SET_UINT('i', "info", &help_format, "show info page",
40            HELP_FORMAT_INFO),
41    OPT_END(),
42};
43
44static const char * const builtin_help_usage[] = {
45    "perf help [--all] [--man|--web|--info] [command]",
46    NULL
47};
48
49static enum help_format parse_help_format(const char *format)
50{
51    if (!strcmp(format, "man"))
52        return HELP_FORMAT_MAN;
53    if (!strcmp(format, "info"))
54        return HELP_FORMAT_INFO;
55    if (!strcmp(format, "web") || !strcmp(format, "html"))
56        return HELP_FORMAT_WEB;
57    die("unrecognized help format '%s'", format);
58}
59
60static const char *get_man_viewer_info(const char *name)
61{
62    struct man_viewer_info_list *viewer;
63
64    for (viewer = man_viewer_info_list; viewer; viewer = viewer->next) {
65        if (!strcasecmp(name, viewer->name))
66            return viewer->info;
67    }
68    return NULL;
69}
70
71static int check_emacsclient_version(void)
72{
73    struct strbuf buffer = STRBUF_INIT;
74    struct child_process ec_process;
75    const char *argv_ec[] = { "emacsclient", "--version", NULL };
76    int version;
77
78    /* emacsclient prints its version number on stderr */
79    memset(&ec_process, 0, sizeof(ec_process));
80    ec_process.argv = argv_ec;
81    ec_process.err = -1;
82    ec_process.stdout_to_stderr = 1;
83    if (start_command(&ec_process)) {
84        fprintf(stderr, "Failed to start emacsclient.\n");
85        return -1;
86    }
87    strbuf_read(&buffer, ec_process.err, 20);
88    close(ec_process.err);
89
90    /*
91     * Don't bother checking return value, because "emacsclient --version"
92     * seems to always exits with code 1.
93     */
94    finish_command(&ec_process);
95
96    if (prefixcmp(buffer.buf, "emacsclient")) {
97        fprintf(stderr, "Failed to parse emacsclient version.\n");
98        strbuf_release(&buffer);
99        return -1;
100    }
101
102    strbuf_remove(&buffer, 0, strlen("emacsclient"));
103    version = atoi(buffer.buf);
104
105    if (version < 22) {
106        fprintf(stderr,
107            "emacsclient version '%d' too old (< 22).\n",
108            version);
109        strbuf_release(&buffer);
110        return -1;
111    }
112
113    strbuf_release(&buffer);
114    return 0;
115}
116
117static void exec_woman_emacs(const char *path, const char *page)
118{
119    if (!check_emacsclient_version()) {
120        /* This works only with emacsclient version >= 22. */
121        struct strbuf man_page = STRBUF_INIT;
122
123        if (!path)
124            path = "emacsclient";
125        strbuf_addf(&man_page, "(woman \"%s\")", page);
126        execlp(path, "emacsclient", "-e", man_page.buf, NULL);
127        warning("failed to exec '%s': %s", path, strerror(errno));
128    }
129}
130
131static void exec_man_konqueror(const char *path, const char *page)
132{
133    const char *display = getenv("DISPLAY");
134    if (display && *display) {
135        struct strbuf man_page = STRBUF_INIT;
136        const char *filename = "kfmclient";
137
138        /* It's simpler to launch konqueror using kfmclient. */
139        if (path) {
140            const char *file = strrchr(path, '/');
141            if (file && !strcmp(file + 1, "konqueror")) {
142                char *new = strdup(path);
143                char *dest = strrchr(new, '/');
144
145                /* strlen("konqueror") == strlen("kfmclient") */
146                strcpy(dest + 1, "kfmclient");
147                path = new;
148            }
149            if (file)
150                filename = file;
151        } else
152            path = "kfmclient";
153        strbuf_addf(&man_page, "man:%s(1)", page);
154        execlp(path, filename, "newTab", man_page.buf, NULL);
155        warning("failed to exec '%s': %s", path, strerror(errno));
156    }
157}
158
159static void exec_man_man(const char *path, const char *page)
160{
161    if (!path)
162        path = "man";
163    execlp(path, "man", page, NULL);
164    warning("failed to exec '%s': %s", path, strerror(errno));
165}
166
167static void exec_man_cmd(const char *cmd, const char *page)
168{
169    struct strbuf shell_cmd = STRBUF_INIT;
170    strbuf_addf(&shell_cmd, "%s %s", cmd, page);
171    execl("/bin/sh", "sh", "-c", shell_cmd.buf, NULL);
172    warning("failed to exec '%s': %s", cmd, strerror(errno));
173}
174
175static void add_man_viewer(const char *name)
176{
177    struct man_viewer_list **p = &man_viewer_list;
178    size_t len = strlen(name);
179
180    while (*p)
181        p = &((*p)->next);
182    *p = zalloc(sizeof(**p) + len + 1);
183    strncpy((*p)->name, name, len);
184}
185
186static int supported_man_viewer(const char *name, size_t len)
187{
188    return (!strncasecmp("man", name, len) ||
189        !strncasecmp("woman", name, len) ||
190        !strncasecmp("konqueror", name, len));
191}
192
193static void do_add_man_viewer_info(const char *name,
194                   size_t len,
195                   const char *value)
196{
197    struct man_viewer_info_list *new = zalloc(sizeof(*new) + len + 1);
198
199    strncpy(new->name, name, len);
200    new->info = strdup(value);
201    new->next = man_viewer_info_list;
202    man_viewer_info_list = new;
203}
204
205static int add_man_viewer_path(const char *name,
206                   size_t len,
207                   const char *value)
208{
209    if (supported_man_viewer(name, len))
210        do_add_man_viewer_info(name, len, value);
211    else
212        warning("'%s': path for unsupported man viewer.\n"
213            "Please consider using 'man.<tool>.cmd' instead.",
214            name);
215
216    return 0;
217}
218
219static int add_man_viewer_cmd(const char *name,
220                  size_t len,
221                  const char *value)
222{
223    if (supported_man_viewer(name, len))
224        warning("'%s': cmd for supported man viewer.\n"
225            "Please consider using 'man.<tool>.path' instead.",
226            name);
227    else
228        do_add_man_viewer_info(name, len, value);
229
230    return 0;
231}
232
233static int add_man_viewer_info(const char *var, const char *value)
234{
235    const char *name = var + 4;
236    const char *subkey = strrchr(name, '.');
237
238    if (!subkey)
239        return error("Config with no key for man viewer: %s", name);
240
241    if (!strcmp(subkey, ".path")) {
242        if (!value)
243            return config_error_nonbool(var);
244        return add_man_viewer_path(name, subkey - name, value);
245    }
246    if (!strcmp(subkey, ".cmd")) {
247        if (!value)
248            return config_error_nonbool(var);
249        return add_man_viewer_cmd(name, subkey - name, value);
250    }
251
252    warning("'%s': unsupported man viewer sub key.", subkey);
253    return 0;
254}
255
256static int perf_help_config(const char *var, const char *value, void *cb)
257{
258    if (!strcmp(var, "help.format")) {
259        if (!value)
260            return config_error_nonbool(var);
261        help_format = parse_help_format(value);
262        return 0;
263    }
264    if (!strcmp(var, "man.viewer")) {
265        if (!value)
266            return config_error_nonbool(var);
267        add_man_viewer(value);
268        return 0;
269    }
270    if (!prefixcmp(var, "man."))
271        return add_man_viewer_info(var, value);
272
273    return perf_default_config(var, value, cb);
274}
275
276static struct cmdnames main_cmds, other_cmds;
277
278void list_common_cmds_help(void)
279{
280    unsigned int i, longest = 0;
281
282    for (i = 0; i < ARRAY_SIZE(common_cmds); i++) {
283        if (longest < strlen(common_cmds[i].name))
284            longest = strlen(common_cmds[i].name);
285    }
286
287    puts(" The most commonly used perf commands are:");
288    for (i = 0; i < ARRAY_SIZE(common_cmds); i++) {
289        printf(" %-*s ", longest, common_cmds[i].name);
290        puts(common_cmds[i].help);
291    }
292}
293
294static int is_perf_command(const char *s)
295{
296    return is_in_cmdlist(&main_cmds, s) ||
297        is_in_cmdlist(&other_cmds, s);
298}
299
300static const char *prepend(const char *prefix, const char *cmd)
301{
302    size_t pre_len = strlen(prefix);
303    size_t cmd_len = strlen(cmd);
304    char *p = malloc(pre_len + cmd_len + 1);
305    memcpy(p, prefix, pre_len);
306    strcpy(p + pre_len, cmd);
307    return p;
308}
309
310static const char *cmd_to_page(const char *perf_cmd)
311{
312    if (!perf_cmd)
313        return "perf";
314    else if (!prefixcmp(perf_cmd, "perf"))
315        return perf_cmd;
316    else
317        return prepend("perf-", perf_cmd);
318}
319
320static void setup_man_path(void)
321{
322    struct strbuf new_path = STRBUF_INIT;
323    const char *old_path = getenv("MANPATH");
324
325    /* We should always put ':' after our path. If there is no
326     * old_path, the ':' at the end will let 'man' to try
327     * system-wide paths after ours to find the manual page. If
328     * there is old_path, we need ':' as delimiter. */
329    strbuf_addstr(&new_path, system_path(PERF_MAN_PATH));
330    strbuf_addch(&new_path, ':');
331    if (old_path)
332        strbuf_addstr(&new_path, old_path);
333
334    setenv("MANPATH", new_path.buf, 1);
335
336    strbuf_release(&new_path);
337}
338
339static void exec_viewer(const char *name, const char *page)
340{
341    const char *info = get_man_viewer_info(name);
342
343    if (!strcasecmp(name, "man"))
344        exec_man_man(info, page);
345    else if (!strcasecmp(name, "woman"))
346        exec_woman_emacs(info, page);
347    else if (!strcasecmp(name, "konqueror"))
348        exec_man_konqueror(info, page);
349    else if (info)
350        exec_man_cmd(info, page);
351    else
352        warning("'%s': unknown man viewer.", name);
353}
354
355static void show_man_page(const char *perf_cmd)
356{
357    struct man_viewer_list *viewer;
358    const char *page = cmd_to_page(perf_cmd);
359    const char *fallback = getenv("PERF_MAN_VIEWER");
360
361    setup_man_path();
362    for (viewer = man_viewer_list; viewer; viewer = viewer->next)
363        exec_viewer(viewer->name, page); /* will return when unable */
364
365    if (fallback)
366        exec_viewer(fallback, page);
367    exec_viewer("man", page);
368    die("no man viewer handled the request");
369}
370
371static void show_info_page(const char *perf_cmd)
372{
373    const char *page = cmd_to_page(perf_cmd);
374    setenv("INFOPATH", system_path(PERF_INFO_PATH), 1);
375    execlp("info", "info", "perfman", page, NULL);
376}
377
378static void get_html_page_path(struct strbuf *page_path, const char *page)
379{
380    struct stat st;
381    const char *html_path = system_path(PERF_HTML_PATH);
382
383    /* Check that we have a perf documentation directory. */
384    if (stat(mkpath("%s/perf.html", html_path), &st)
385        || !S_ISREG(st.st_mode))
386        die("'%s': not a documentation directory.", html_path);
387
388    strbuf_init(page_path, 0);
389    strbuf_addf(page_path, "%s/%s.html", html_path, page);
390}
391
392/*
393 * If open_html is not defined in a platform-specific way (see for
394 * example compat/mingw.h), we use the script web--browse to display
395 * HTML.
396 */
397#ifndef open_html
398static void open_html(const char *path)
399{
400    execl_perf_cmd("web--browse", "-c", "help.browser", path, NULL);
401}
402#endif
403
404static void show_html_page(const char *perf_cmd)
405{
406    const char *page = cmd_to_page(perf_cmd);
407    struct strbuf page_path; /* it leaks but we exec bellow */
408
409    get_html_page_path(&page_path, page);
410
411    open_html(page_path.buf);
412}
413
414int cmd_help(int argc, const char **argv, const char *prefix __used)
415{
416    const char *alias;
417
418    load_command_list("perf-", &main_cmds, &other_cmds);
419
420    perf_config(perf_help_config, NULL);
421
422    argc = parse_options(argc, argv, builtin_help_options,
423            builtin_help_usage, 0);
424
425    if (show_all) {
426        printf("\n usage: %s\n\n", perf_usage_string);
427        list_commands("perf commands", &main_cmds, &other_cmds);
428        printf(" %s\n\n", perf_more_info_string);
429        return 0;
430    }
431
432    if (!argv[0]) {
433        printf("\n usage: %s\n\n", perf_usage_string);
434        list_common_cmds_help();
435        printf("\n %s\n\n", perf_more_info_string);
436        return 0;
437    }
438
439    alias = alias_lookup(argv[0]);
440    if (alias && !is_perf_command(argv[0])) {
441        printf("`perf %s' is aliased to `%s'\n", argv[0], alias);
442        return 0;
443    }
444
445    switch (help_format) {
446    case HELP_FORMAT_MAN:
447        show_man_page(argv[0]);
448        break;
449    case HELP_FORMAT_INFO:
450        show_info_page(argv[0]);
451        break;
452    case HELP_FORMAT_WEB:
453        show_html_page(argv[0]);
454    default:
455        break;
456    }
457
458    return 0;
459}
460

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