xref: /linux/tools/lib/subcmd/help.c (revision f4f346c3465949ebba80c6cc52cd8d2eeaa545fd)
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 <assert.h>
13 #include "subcmd-util.h"
14 #include "help.h"
15 #include "exec-cmd.h"
16 
add_cmdname(struct cmdnames * cmds,const char * name,size_t len)17 void add_cmdname(struct cmdnames *cmds, const char *name, size_t len)
18 {
19 	struct cmdname *ent = malloc(sizeof(*ent) + len + 1);
20 	if (!ent)
21 		return;
22 
23 	ent->len = len;
24 	memcpy(ent->name, name, len);
25 	ent->name[len] = 0;
26 
27 	ALLOC_GROW(cmds->names, cmds->cnt + 1, cmds->alloc);
28 	cmds->names[cmds->cnt++] = ent;
29 }
30 
clean_cmdnames(struct cmdnames * cmds)31 void clean_cmdnames(struct cmdnames *cmds)
32 {
33 	unsigned int i;
34 
35 	for (i = 0; i < cmds->cnt; ++i)
36 		zfree(&cmds->names[i]);
37 	zfree(&cmds->names);
38 	cmds->cnt = 0;
39 	cmds->alloc = 0;
40 }
41 
cmdname_compare(const void * a_,const void * b_)42 int cmdname_compare(const void *a_, const void *b_)
43 {
44 	struct cmdname *a = *(struct cmdname **)a_;
45 	struct cmdname *b = *(struct cmdname **)b_;
46 	return strcmp(a->name, b->name);
47 }
48 
uniq(struct cmdnames * cmds)49 void uniq(struct cmdnames *cmds)
50 {
51 	unsigned int i, j;
52 
53 	if (!cmds->cnt)
54 		return;
55 
56 	for (i = 1; i < cmds->cnt; i++) {
57 		if (!strcmp(cmds->names[i]->name, cmds->names[i-1]->name))
58 			zfree(&cmds->names[i - 1]);
59 	}
60 	for (i = 0, j = 0; i < cmds->cnt; i++) {
61 		if (cmds->names[i]) {
62 			if (i == j)
63 				j++;
64 			else
65 				cmds->names[j++] = cmds->names[i];
66 		}
67 	}
68 	cmds->cnt = j;
69 	while (j < i)
70 		cmds->names[j++] = NULL;
71 }
72 
exclude_cmds(struct cmdnames * cmds,struct cmdnames * excludes)73 void exclude_cmds(struct cmdnames *cmds, struct cmdnames *excludes)
74 {
75 	size_t ci, cj, ei;
76 	int cmp;
77 
78 	ci = cj = ei = 0;
79 	while (ci < cmds->cnt && ei < excludes->cnt) {
80 		cmp = strcmp(cmds->names[ci]->name, excludes->names[ei]->name);
81 		if (cmp < 0) {
82 			if (ci == cj) {
83 				ci++;
84 				cj++;
85 			} else {
86 				cmds->names[cj++] = cmds->names[ci];
87 				cmds->names[ci++] = NULL;
88 			}
89 		} else if (cmp == 0) {
90 			zfree(&cmds->names[ci]);
91 			ci++;
92 			ei++;
93 		} else if (cmp > 0) {
94 			ei++;
95 		}
96 	}
97 	if (ci != cj) {
98 		while (ci < cmds->cnt) {
99 			cmds->names[cj++] = cmds->names[ci];
100 			cmds->names[ci++] = NULL;
101 		}
102 	}
103 	for (ci = cj; ci < cmds->cnt; ci++)
104 		assert(cmds->names[ci] == NULL);
105 	cmds->cnt = cj;
106 }
107 
get_term_dimensions(struct winsize * ws)108 static void get_term_dimensions(struct winsize *ws)
109 {
110 	char *s = getenv("LINES");
111 
112 	if (s != NULL) {
113 		ws->ws_row = atoi(s);
114 		s = getenv("COLUMNS");
115 		if (s != NULL) {
116 			ws->ws_col = atoi(s);
117 			if (ws->ws_row && ws->ws_col)
118 				return;
119 		}
120 	}
121 #ifdef TIOCGWINSZ
122 	if (ioctl(1, TIOCGWINSZ, ws) == 0 &&
123 	    ws->ws_row && ws->ws_col)
124 		return;
125 #endif
126 	ws->ws_row = 25;
127 	ws->ws_col = 80;
128 }
129 
pretty_print_string_list(struct cmdnames * cmds,int longest)130 static void pretty_print_string_list(struct cmdnames *cmds, int longest)
131 {
132 	int cols = 1, rows;
133 	int space = longest + 1; /* min 1 SP between words */
134 	struct winsize win;
135 	int max_cols;
136 	int i, j;
137 
138 	get_term_dimensions(&win);
139 	max_cols = win.ws_col - 1; /* don't print *on* the edge */
140 
141 	if (space < max_cols)
142 		cols = max_cols / space;
143 	rows = (cmds->cnt + cols - 1) / cols;
144 
145 	for (i = 0; i < rows; i++) {
146 		printf("  ");
147 
148 		for (j = 0; j < cols; j++) {
149 			unsigned int n = j * rows + i;
150 			unsigned int size = space;
151 
152 			if (n >= cmds->cnt)
153 				break;
154 			if (j == cols-1 || n + rows >= cmds->cnt)
155 				size = 1;
156 			printf("%-*s", size, cmds->names[n]->name);
157 		}
158 		putchar('\n');
159 	}
160 }
161 
is_executable(const char * name)162 static int is_executable(const char *name)
163 {
164 	struct stat st;
165 
166 	if (stat(name, &st) || /* stat, not lstat */
167 	    !S_ISREG(st.st_mode))
168 		return 0;
169 
170 	return st.st_mode & S_IXUSR;
171 }
172 
has_extension(const char * filename,const char * ext)173 static int has_extension(const char *filename, const char *ext)
174 {
175 	size_t len = strlen(filename);
176 	size_t extlen = strlen(ext);
177 
178 	return len > extlen && !memcmp(filename + len - extlen, ext, extlen);
179 }
180 
list_commands_in_dir(struct cmdnames * cmds,const char * path,const char * prefix)181 static void list_commands_in_dir(struct cmdnames *cmds,
182 					 const char *path,
183 					 const char *prefix)
184 {
185 	int prefix_len;
186 	DIR *dir = opendir(path);
187 	struct dirent *de;
188 	char *buf = NULL;
189 
190 	if (!dir)
191 		return;
192 	if (!prefix)
193 		prefix = "perf-";
194 	prefix_len = strlen(prefix);
195 
196 	astrcatf(&buf, "%s/", path);
197 
198 	while ((de = readdir(dir)) != NULL) {
199 		int entlen;
200 
201 		if (!strstarts(de->d_name, prefix))
202 			continue;
203 
204 		astrcat(&buf, de->d_name);
205 		if (!is_executable(buf))
206 			continue;
207 
208 		entlen = strlen(de->d_name) - prefix_len;
209 		if (has_extension(de->d_name, ".exe"))
210 			entlen -= 4;
211 
212 		add_cmdname(cmds, de->d_name + prefix_len, entlen);
213 	}
214 	closedir(dir);
215 	free(buf);
216 }
217 
load_command_list(const char * prefix,struct cmdnames * main_cmds,struct cmdnames * other_cmds)218 void load_command_list(const char *prefix,
219 		struct cmdnames *main_cmds,
220 		struct cmdnames *other_cmds)
221 {
222 	const char *env_path = getenv("PATH");
223 	char *exec_path = get_argv_exec_path();
224 
225 	if (exec_path) {
226 		list_commands_in_dir(main_cmds, exec_path, prefix);
227 		qsort(main_cmds->names, main_cmds->cnt,
228 		      sizeof(*main_cmds->names), cmdname_compare);
229 		uniq(main_cmds);
230 	}
231 
232 	if (env_path) {
233 		char *paths, *path, *colon;
234 		path = paths = strdup(env_path);
235 		while (1) {
236 			if ((colon = strchr(path, ':')))
237 				*colon = 0;
238 			if (!exec_path || strcmp(path, exec_path))
239 				list_commands_in_dir(other_cmds, path, prefix);
240 
241 			if (!colon)
242 				break;
243 			path = colon + 1;
244 		}
245 		free(paths);
246 
247 		qsort(other_cmds->names, other_cmds->cnt,
248 		      sizeof(*other_cmds->names), cmdname_compare);
249 		uniq(other_cmds);
250 	}
251 	free(exec_path);
252 	exclude_cmds(other_cmds, main_cmds);
253 }
254 
list_commands(const char * title,struct cmdnames * main_cmds,struct cmdnames * other_cmds)255 void list_commands(const char *title, struct cmdnames *main_cmds,
256 		   struct cmdnames *other_cmds)
257 {
258 	unsigned int i, longest = 0;
259 
260 	for (i = 0; i < main_cmds->cnt; i++)
261 		if (longest < main_cmds->names[i]->len)
262 			longest = main_cmds->names[i]->len;
263 	for (i = 0; i < other_cmds->cnt; i++)
264 		if (longest < other_cmds->names[i]->len)
265 			longest = other_cmds->names[i]->len;
266 
267 	if (main_cmds->cnt) {
268 		char *exec_path = get_argv_exec_path();
269 		printf("available %s in '%s'\n", title, exec_path);
270 		printf("----------------");
271 		mput_char('-', strlen(title) + strlen(exec_path));
272 		putchar('\n');
273 		pretty_print_string_list(main_cmds, longest);
274 		putchar('\n');
275 		free(exec_path);
276 	}
277 
278 	if (other_cmds->cnt) {
279 		printf("%s available from elsewhere on your $PATH\n", title);
280 		printf("---------------------------------------");
281 		mput_char('-', strlen(title));
282 		putchar('\n');
283 		pretty_print_string_list(other_cmds, longest);
284 		putchar('\n');
285 	}
286 }
287 
is_in_cmdlist(struct cmdnames * c,const char * s)288 int is_in_cmdlist(struct cmdnames *c, const char *s)
289 {
290 	unsigned int i;
291 
292 	for (i = 0; i < c->cnt; i++)
293 		if (!strcmp(s, c->names[i]->name))
294 			return 1;
295 	return 0;
296 }
297