xref: /linux/tools/lib/subcmd/help.c (revision 5aca7966d2a7255ba92fd5e63268dd767b223aa5)
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 	if (!excludes->cnt)
79 		return;
80 
81 	ci = cj = ei = 0;
82 	while (ci < cmds->cnt && ei < excludes->cnt) {
83 		cmp = strcmp(cmds->names[ci]->name, excludes->names[ei]->name);
84 		if (cmp < 0) {
85 			if (ci == cj) {
86 				ci++;
87 				cj++;
88 			} else {
89 				cmds->names[cj++] = cmds->names[ci];
90 				cmds->names[ci++] = NULL;
91 			}
92 		} else if (cmp == 0) {
93 			zfree(&cmds->names[ci]);
94 			ci++;
95 			ei++;
96 		} else if (cmp > 0) {
97 			ei++;
98 		}
99 	}
100 	if (ci != cj) {
101 		while (ci < cmds->cnt) {
102 			cmds->names[cj++] = cmds->names[ci];
103 			cmds->names[ci++] = NULL;
104 		}
105 	}
106 	for (ci = cj; ci < cmds->cnt; ci++)
107 		assert(cmds->names[ci] == NULL);
108 	cmds->cnt = cj;
109 }
110 
get_term_dimensions(struct winsize * ws)111 static void get_term_dimensions(struct winsize *ws)
112 {
113 	char *s = getenv("LINES");
114 
115 	if (s != NULL) {
116 		ws->ws_row = atoi(s);
117 		s = getenv("COLUMNS");
118 		if (s != NULL) {
119 			ws->ws_col = atoi(s);
120 			if (ws->ws_row && ws->ws_col)
121 				return;
122 		}
123 	}
124 #ifdef TIOCGWINSZ
125 	if (ioctl(1, TIOCGWINSZ, ws) == 0 &&
126 	    ws->ws_row && ws->ws_col)
127 		return;
128 #endif
129 	ws->ws_row = 25;
130 	ws->ws_col = 80;
131 }
132 
pretty_print_string_list(struct cmdnames * cmds,int longest)133 static void pretty_print_string_list(struct cmdnames *cmds, int longest)
134 {
135 	int cols = 1, rows;
136 	int space = longest + 1; /* min 1 SP between words */
137 	struct winsize win;
138 	int max_cols;
139 	int i, j;
140 
141 	get_term_dimensions(&win);
142 	max_cols = win.ws_col - 1; /* don't print *on* the edge */
143 
144 	if (space < max_cols)
145 		cols = max_cols / space;
146 	rows = (cmds->cnt + cols - 1) / cols;
147 
148 	for (i = 0; i < rows; i++) {
149 		printf("  ");
150 
151 		for (j = 0; j < cols; j++) {
152 			unsigned int n = j * rows + i;
153 			unsigned int size = space;
154 
155 			if (n >= cmds->cnt)
156 				break;
157 			if (j == cols-1 || n + rows >= cmds->cnt)
158 				size = 1;
159 			printf("%-*s", size, cmds->names[n]->name);
160 		}
161 		putchar('\n');
162 	}
163 }
164 
is_executable(const char * name)165 static int is_executable(const char *name)
166 {
167 	struct stat st;
168 
169 	if (stat(name, &st) || /* stat, not lstat */
170 	    !S_ISREG(st.st_mode))
171 		return 0;
172 
173 	return st.st_mode & S_IXUSR;
174 }
175 
has_extension(const char * filename,const char * ext)176 static int has_extension(const char *filename, const char *ext)
177 {
178 	size_t len = strlen(filename);
179 	size_t extlen = strlen(ext);
180 
181 	return len > extlen && !memcmp(filename + len - extlen, ext, extlen);
182 }
183 
list_commands_in_dir(struct cmdnames * cmds,const char * path,const char * prefix)184 static void list_commands_in_dir(struct cmdnames *cmds,
185 					 const char *path,
186 					 const char *prefix)
187 {
188 	int prefix_len;
189 	DIR *dir = opendir(path);
190 	struct dirent *de;
191 	char *buf = NULL;
192 
193 	if (!dir)
194 		return;
195 	if (!prefix)
196 		prefix = "perf-";
197 	prefix_len = strlen(prefix);
198 
199 	astrcatf(&buf, "%s/", path);
200 
201 	while ((de = readdir(dir)) != NULL) {
202 		int entlen;
203 
204 		if (!strstarts(de->d_name, prefix))
205 			continue;
206 
207 		astrcat(&buf, de->d_name);
208 		if (!is_executable(buf))
209 			continue;
210 
211 		entlen = strlen(de->d_name) - prefix_len;
212 		if (has_extension(de->d_name, ".exe"))
213 			entlen -= 4;
214 
215 		add_cmdname(cmds, de->d_name + prefix_len, entlen);
216 	}
217 	closedir(dir);
218 	free(buf);
219 }
220 
load_command_list(const char * prefix,struct cmdnames * main_cmds,struct cmdnames * other_cmds)221 void load_command_list(const char *prefix,
222 		struct cmdnames *main_cmds,
223 		struct cmdnames *other_cmds)
224 {
225 	const char *env_path = getenv("PATH");
226 	char *exec_path = get_argv_exec_path();
227 
228 	if (exec_path) {
229 		list_commands_in_dir(main_cmds, exec_path, prefix);
230 		qsort(main_cmds->names, main_cmds->cnt,
231 		      sizeof(*main_cmds->names), cmdname_compare);
232 		uniq(main_cmds);
233 	}
234 
235 	if (env_path) {
236 		char *paths, *path, *colon;
237 		path = paths = strdup(env_path);
238 		while (1) {
239 			if ((colon = strchr(path, ':')))
240 				*colon = 0;
241 			if (!exec_path || strcmp(path, exec_path))
242 				list_commands_in_dir(other_cmds, path, prefix);
243 
244 			if (!colon)
245 				break;
246 			path = colon + 1;
247 		}
248 		free(paths);
249 
250 		qsort(other_cmds->names, other_cmds->cnt,
251 		      sizeof(*other_cmds->names), cmdname_compare);
252 		uniq(other_cmds);
253 	}
254 	free(exec_path);
255 	exclude_cmds(other_cmds, main_cmds);
256 }
257 
list_commands(const char * title,struct cmdnames * main_cmds,struct cmdnames * other_cmds)258 void list_commands(const char *title, struct cmdnames *main_cmds,
259 		   struct cmdnames *other_cmds)
260 {
261 	unsigned int i, longest = 0;
262 
263 	for (i = 0; i < main_cmds->cnt; i++)
264 		if (longest < main_cmds->names[i]->len)
265 			longest = main_cmds->names[i]->len;
266 	for (i = 0; i < other_cmds->cnt; i++)
267 		if (longest < other_cmds->names[i]->len)
268 			longest = other_cmds->names[i]->len;
269 
270 	if (main_cmds->cnt) {
271 		char *exec_path = get_argv_exec_path();
272 		printf("available %s in '%s'\n", title, exec_path);
273 		printf("----------------");
274 		mput_char('-', strlen(title) + strlen(exec_path));
275 		putchar('\n');
276 		pretty_print_string_list(main_cmds, longest);
277 		putchar('\n');
278 		free(exec_path);
279 	}
280 
281 	if (other_cmds->cnt) {
282 		printf("%s available from elsewhere on your $PATH\n", title);
283 		printf("---------------------------------------");
284 		mput_char('-', strlen(title));
285 		putchar('\n');
286 		pretty_print_string_list(other_cmds, longest);
287 		putchar('\n');
288 	}
289 }
290 
is_in_cmdlist(struct cmdnames * c,const char * s)291 int is_in_cmdlist(struct cmdnames *c, const char *s)
292 {
293 	unsigned int i;
294 
295 	for (i = 0; i < c->cnt; i++)
296 		if (!strcmp(s, c->names[i]->name))
297 			return 1;
298 	return 0;
299 }
300