xref: /kernel/linux/linux-5.10/tools/lib/subcmd/help.c (revision 8c2ecf20) 
1// SPDX-License-Identifier: GPL-2.0
2#include <stdio.h>
3#include <stdlib.h>
4#include <string.h>
5#include <linux/string.h>
6#include <termios.h>
7#include <sys/ioctl.h>
8#include <sys/types.h>
9#include <sys/stat.h>
10#include <unistd.h>
11#include <dirent.h>
12#include "subcmd-util.h"
13#include "help.h"
14#include "exec-cmd.h"
15
16void add_cmdname(struct cmdnames *cmds, const char *name, size_t len)
17{
18	struct cmdname *ent = malloc(sizeof(*ent) + len + 1);
19
20	ent->len = len;
21	memcpy(ent->name, name, len);
22	ent->name[len] = 0;
23
24	ALLOC_GROW(cmds->names, cmds->cnt + 1, cmds->alloc);
25	cmds->names[cmds->cnt++] = ent;
26}
27
28void clean_cmdnames(struct cmdnames *cmds)
29{
30	unsigned int i;
31
32	for (i = 0; i < cmds->cnt; ++i)
33		zfree(&cmds->names[i]);
34	zfree(&cmds->names);
35	cmds->cnt = 0;
36	cmds->alloc = 0;
37}
38
39int cmdname_compare(const void *a_, const void *b_)
40{
41	struct cmdname *a = *(struct cmdname **)a_;
42	struct cmdname *b = *(struct cmdname **)b_;
43	return strcmp(a->name, b->name);
44}
45
46void uniq(struct cmdnames *cmds)
47{
48	unsigned int i, j;
49
50	if (!cmds->cnt)
51		return;
52
53	for (i = 1; i < cmds->cnt; i++) {
54		if (!strcmp(cmds->names[i]->name, cmds->names[i-1]->name))
55			zfree(&cmds->names[i - 1]);
56	}
57	for (i = 0, j = 0; i < cmds->cnt; i++) {
58		if (cmds->names[i]) {
59			if (i == j)
60				j++;
61			else
62				cmds->names[j++] = cmds->names[i];
63		}
64	}
65	cmds->cnt = j;
66	while (j < i)
67		cmds->names[j++] = NULL;
68}
69
70void exclude_cmds(struct cmdnames *cmds, struct cmdnames *excludes)
71{
72	size_t ci, cj, ei;
73	int cmp;
74
75	ci = cj = ei = 0;
76	while (ci < cmds->cnt && ei < excludes->cnt) {
77		cmp = strcmp(cmds->names[ci]->name, excludes->names[ei]->name);
78		if (cmp < 0) {
79			cmds->names[cj++] = cmds->names[ci++];
80		} else if (cmp == 0) {
81			ci++;
82			ei++;
83		} else if (cmp > 0) {
84			ei++;
85		}
86	}
87
88	while (ci < cmds->cnt)
89		cmds->names[cj++] = cmds->names[ci++];
90
91	cmds->cnt = cj;
92}
93
94static void get_term_dimensions(struct winsize *ws)
95{
96	char *s = getenv("LINES");
97
98	if (s != NULL) {
99		ws->ws_row = atoi(s);
100		s = getenv("COLUMNS");
101		if (s != NULL) {
102			ws->ws_col = atoi(s);
103			if (ws->ws_row && ws->ws_col)
104				return;
105		}
106	}
107#ifdef TIOCGWINSZ
108	if (ioctl(1, TIOCGWINSZ, ws) == 0 &&
109	    ws->ws_row && ws->ws_col)
110		return;
111#endif
112	ws->ws_row = 25;
113	ws->ws_col = 80;
114}
115
116static void pretty_print_string_list(struct cmdnames *cmds, int longest)
117{
118	int cols = 1, rows;
119	int space = longest + 1; /* min 1 SP between words */
120	struct winsize win;
121	int max_cols;
122	int i, j;
123
124	get_term_dimensions(&win);
125	max_cols = win.ws_col - 1; /* don't print *on* the edge */
126
127	if (space < max_cols)
128		cols = max_cols / space;
129	rows = (cmds->cnt + cols - 1) / cols;
130
131	for (i = 0; i < rows; i++) {
132		printf("  ");
133
134		for (j = 0; j < cols; j++) {
135			unsigned int n = j * rows + i;
136			unsigned int size = space;
137
138			if (n >= cmds->cnt)
139				break;
140			if (j == cols-1 || n + rows >= cmds->cnt)
141				size = 1;
142			printf("%-*s", size, cmds->names[n]->name);
143		}
144		putchar('\n');
145	}
146}
147
148static int is_executable(const char *name)
149{
150	struct stat st;
151
152	if (stat(name, &st) || /* stat, not lstat */
153	    !S_ISREG(st.st_mode))
154		return 0;
155
156	return st.st_mode & S_IXUSR;
157}
158
159static int has_extension(const char *filename, const char *ext)
160{
161	size_t len = strlen(filename);
162	size_t extlen = strlen(ext);
163
164	return len > extlen && !memcmp(filename + len - extlen, ext, extlen);
165}
166
167static void list_commands_in_dir(struct cmdnames *cmds,
168					 const char *path,
169					 const char *prefix)
170{
171	int prefix_len;
172	DIR *dir = opendir(path);
173	struct dirent *de;
174	char *buf = NULL;
175
176	if (!dir)
177		return;
178	if (!prefix)
179		prefix = "perf-";
180	prefix_len = strlen(prefix);
181
182	astrcatf(&buf, "%s/", path);
183
184	while ((de = readdir(dir)) != NULL) {
185		int entlen;
186
187		if (!strstarts(de->d_name, prefix))
188			continue;
189
190		astrcat(&buf, de->d_name);
191		if (!is_executable(buf))
192			continue;
193
194		entlen = strlen(de->d_name) - prefix_len;
195		if (has_extension(de->d_name, ".exe"))
196			entlen -= 4;
197
198		add_cmdname(cmds, de->d_name + prefix_len, entlen);
199	}
200	closedir(dir);
201	free(buf);
202}
203
204void load_command_list(const char *prefix,
205		struct cmdnames *main_cmds,
206		struct cmdnames *other_cmds)
207{
208	const char *env_path = getenv("PATH");
209	char *exec_path = get_argv_exec_path();
210
211	if (exec_path) {
212		list_commands_in_dir(main_cmds, exec_path, prefix);
213		qsort(main_cmds->names, main_cmds->cnt,
214		      sizeof(*main_cmds->names), cmdname_compare);
215		uniq(main_cmds);
216	}
217
218	if (env_path) {
219		char *paths, *path, *colon;
220		path = paths = strdup(env_path);
221		while (1) {
222			if ((colon = strchr(path, ':')))
223				*colon = 0;
224			if (!exec_path || strcmp(path, exec_path))
225				list_commands_in_dir(other_cmds, path, prefix);
226
227			if (!colon)
228				break;
229			path = colon + 1;
230		}
231		free(paths);
232
233		qsort(other_cmds->names, other_cmds->cnt,
234		      sizeof(*other_cmds->names), cmdname_compare);
235		uniq(other_cmds);
236	}
237	free(exec_path);
238	exclude_cmds(other_cmds, main_cmds);
239}
240
241void list_commands(const char *title, struct cmdnames *main_cmds,
242		   struct cmdnames *other_cmds)
243{
244	unsigned int i, longest = 0;
245
246	for (i = 0; i < main_cmds->cnt; i++)
247		if (longest < main_cmds->names[i]->len)
248			longest = main_cmds->names[i]->len;
249	for (i = 0; i < other_cmds->cnt; i++)
250		if (longest < other_cmds->names[i]->len)
251			longest = other_cmds->names[i]->len;
252
253	if (main_cmds->cnt) {
254		char *exec_path = get_argv_exec_path();
255		printf("available %s in '%s'\n", title, exec_path);
256		printf("----------------");
257		mput_char('-', strlen(title) + strlen(exec_path));
258		putchar('\n');
259		pretty_print_string_list(main_cmds, longest);
260		putchar('\n');
261		free(exec_path);
262	}
263
264	if (other_cmds->cnt) {
265		printf("%s available from elsewhere on your $PATH\n", title);
266		printf("---------------------------------------");
267		mput_char('-', strlen(title));
268		putchar('\n');
269		pretty_print_string_list(other_cmds, longest);
270		putchar('\n');
271	}
272}
273
274int is_in_cmdlist(struct cmdnames *c, const char *s)
275{
276	unsigned int i;
277
278	for (i = 0; i < c->cnt; i++)
279		if (!strcmp(s, c->names[i]->name))
280			return 1;
281	return 0;
282}
283