xref: /linux/tools/lib/subcmd/help.c (revision e7d759f31ca295d589f7420719c311870bb3166f)
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 
16 void add_cmdname(struct cmdnames *cmds, const char *name, size_t len)
17 {
18 	struct cmdname *ent = malloc(sizeof(*ent) + len + 1);
19 	if (!ent)
20 		return;
21 
22 	ent->len = len;
23 	memcpy(ent->name, name, len);
24 	ent->name[len] = 0;
25 
26 	ALLOC_GROW(cmds->names, cmds->cnt + 1, cmds->alloc);
27 	cmds->names[cmds->cnt++] = ent;
28 }
29 
30 void clean_cmdnames(struct cmdnames *cmds)
31 {
32 	unsigned int i;
33 
34 	for (i = 0; i < cmds->cnt; ++i)
35 		zfree(&cmds->names[i]);
36 	zfree(&cmds->names);
37 	cmds->cnt = 0;
38 	cmds->alloc = 0;
39 }
40 
41 int cmdname_compare(const void *a_, const void *b_)
42 {
43 	struct cmdname *a = *(struct cmdname **)a_;
44 	struct cmdname *b = *(struct cmdname **)b_;
45 	return strcmp(a->name, b->name);
46 }
47 
48 void uniq(struct cmdnames *cmds)
49 {
50 	unsigned int i, j;
51 
52 	if (!cmds->cnt)
53 		return;
54 
55 	for (i = 1; i < cmds->cnt; i++) {
56 		if (!strcmp(cmds->names[i]->name, cmds->names[i-1]->name))
57 			zfree(&cmds->names[i - 1]);
58 	}
59 	for (i = 0, j = 0; i < cmds->cnt; i++) {
60 		if (cmds->names[i]) {
61 			if (i == j)
62 				j++;
63 			else
64 				cmds->names[j++] = cmds->names[i];
65 		}
66 	}
67 	cmds->cnt = j;
68 	while (j < i)
69 		cmds->names[j++] = NULL;
70 }
71 
72 void exclude_cmds(struct cmdnames *cmds, struct cmdnames *excludes)
73 {
74 	size_t ci, cj, ei;
75 	int cmp;
76 
77 	ci = cj = ei = 0;
78 	while (ci < cmds->cnt && ei < excludes->cnt) {
79 		cmp = strcmp(cmds->names[ci]->name, excludes->names[ei]->name);
80 		if (cmp < 0) {
81 			if (ci == cj) {
82 				ci++;
83 				cj++;
84 			} else {
85 				zfree(&cmds->names[cj]);
86 				cmds->names[cj++] = cmds->names[ci++];
87 			}
88 		} else if (cmp == 0) {
89 			ci++;
90 			ei++;
91 		} else if (cmp > 0) {
92 			ei++;
93 		}
94 	}
95 	if (ci != cj) {
96 		while (ci < cmds->cnt) {
97 			zfree(&cmds->names[cj]);
98 			cmds->names[cj++] = cmds->names[ci++];
99 		}
100 	}
101 	for (ci = cj; ci < cmds->cnt; ci++)
102 		zfree(&cmds->names[ci]);
103 	cmds->cnt = cj;
104 }
105 
106 static void get_term_dimensions(struct winsize *ws)
107 {
108 	char *s = getenv("LINES");
109 
110 	if (s != NULL) {
111 		ws->ws_row = atoi(s);
112 		s = getenv("COLUMNS");
113 		if (s != NULL) {
114 			ws->ws_col = atoi(s);
115 			if (ws->ws_row && ws->ws_col)
116 				return;
117 		}
118 	}
119 #ifdef TIOCGWINSZ
120 	if (ioctl(1, TIOCGWINSZ, ws) == 0 &&
121 	    ws->ws_row && ws->ws_col)
122 		return;
123 #endif
124 	ws->ws_row = 25;
125 	ws->ws_col = 80;
126 }
127 
128 static void pretty_print_string_list(struct cmdnames *cmds, int longest)
129 {
130 	int cols = 1, rows;
131 	int space = longest + 1; /* min 1 SP between words */
132 	struct winsize win;
133 	int max_cols;
134 	int i, j;
135 
136 	get_term_dimensions(&win);
137 	max_cols = win.ws_col - 1; /* don't print *on* the edge */
138 
139 	if (space < max_cols)
140 		cols = max_cols / space;
141 	rows = (cmds->cnt + cols - 1) / cols;
142 
143 	for (i = 0; i < rows; i++) {
144 		printf("  ");
145 
146 		for (j = 0; j < cols; j++) {
147 			unsigned int n = j * rows + i;
148 			unsigned int size = space;
149 
150 			if (n >= cmds->cnt)
151 				break;
152 			if (j == cols-1 || n + rows >= cmds->cnt)
153 				size = 1;
154 			printf("%-*s", size, cmds->names[n]->name);
155 		}
156 		putchar('\n');
157 	}
158 }
159 
160 static int is_executable(const char *name)
161 {
162 	struct stat st;
163 
164 	if (stat(name, &st) || /* stat, not lstat */
165 	    !S_ISREG(st.st_mode))
166 		return 0;
167 
168 	return st.st_mode & S_IXUSR;
169 }
170 
171 static int has_extension(const char *filename, const char *ext)
172 {
173 	size_t len = strlen(filename);
174 	size_t extlen = strlen(ext);
175 
176 	return len > extlen && !memcmp(filename + len - extlen, ext, extlen);
177 }
178 
179 static void list_commands_in_dir(struct cmdnames *cmds,
180 					 const char *path,
181 					 const char *prefix)
182 {
183 	int prefix_len;
184 	DIR *dir = opendir(path);
185 	struct dirent *de;
186 	char *buf = NULL;
187 
188 	if (!dir)
189 		return;
190 	if (!prefix)
191 		prefix = "perf-";
192 	prefix_len = strlen(prefix);
193 
194 	astrcatf(&buf, "%s/", path);
195 
196 	while ((de = readdir(dir)) != NULL) {
197 		int entlen;
198 
199 		if (!strstarts(de->d_name, prefix))
200 			continue;
201 
202 		astrcat(&buf, de->d_name);
203 		if (!is_executable(buf))
204 			continue;
205 
206 		entlen = strlen(de->d_name) - prefix_len;
207 		if (has_extension(de->d_name, ".exe"))
208 			entlen -= 4;
209 
210 		add_cmdname(cmds, de->d_name + prefix_len, entlen);
211 	}
212 	closedir(dir);
213 	free(buf);
214 }
215 
216 void load_command_list(const char *prefix,
217 		struct cmdnames *main_cmds,
218 		struct cmdnames *other_cmds)
219 {
220 	const char *env_path = getenv("PATH");
221 	char *exec_path = get_argv_exec_path();
222 
223 	if (exec_path) {
224 		list_commands_in_dir(main_cmds, exec_path, prefix);
225 		qsort(main_cmds->names, main_cmds->cnt,
226 		      sizeof(*main_cmds->names), cmdname_compare);
227 		uniq(main_cmds);
228 	}
229 
230 	if (env_path) {
231 		char *paths, *path, *colon;
232 		path = paths = strdup(env_path);
233 		while (1) {
234 			if ((colon = strchr(path, ':')))
235 				*colon = 0;
236 			if (!exec_path || strcmp(path, exec_path))
237 				list_commands_in_dir(other_cmds, path, prefix);
238 
239 			if (!colon)
240 				break;
241 			path = colon + 1;
242 		}
243 		free(paths);
244 
245 		qsort(other_cmds->names, other_cmds->cnt,
246 		      sizeof(*other_cmds->names), cmdname_compare);
247 		uniq(other_cmds);
248 	}
249 	free(exec_path);
250 	exclude_cmds(other_cmds, main_cmds);
251 }
252 
253 void list_commands(const char *title, struct cmdnames *main_cmds,
254 		   struct cmdnames *other_cmds)
255 {
256 	unsigned int i, longest = 0;
257 
258 	for (i = 0; i < main_cmds->cnt; i++)
259 		if (longest < main_cmds->names[i]->len)
260 			longest = main_cmds->names[i]->len;
261 	for (i = 0; i < other_cmds->cnt; i++)
262 		if (longest < other_cmds->names[i]->len)
263 			longest = other_cmds->names[i]->len;
264 
265 	if (main_cmds->cnt) {
266 		char *exec_path = get_argv_exec_path();
267 		printf("available %s in '%s'\n", title, exec_path);
268 		printf("----------------");
269 		mput_char('-', strlen(title) + strlen(exec_path));
270 		putchar('\n');
271 		pretty_print_string_list(main_cmds, longest);
272 		putchar('\n');
273 		free(exec_path);
274 	}
275 
276 	if (other_cmds->cnt) {
277 		printf("%s available from elsewhere on your $PATH\n", title);
278 		printf("---------------------------------------");
279 		mput_char('-', strlen(title));
280 		putchar('\n');
281 		pretty_print_string_list(other_cmds, longest);
282 		putchar('\n');
283 	}
284 }
285 
286 int is_in_cmdlist(struct cmdnames *c, const char *s)
287 {
288 	unsigned int i;
289 
290 	for (i = 0; i < c->cnt; i++)
291 		if (!strcmp(s, c->names[i]->name))
292 			return 1;
293 	return 0;
294 }
295