xref: /linux/tools/lib/subcmd/help.c (revision 0e9ab8e4d44ae9d9aaf213bfd2c90bbe7289337b)
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 
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 
28 void 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 
39 int 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 
46 void uniq(struct cmdnames *cmds)
47 {
48 	unsigned int i, j;
49 
50 	if (!cmds->cnt)
51 		return;
52 
53 	for (i = j = 1; i < cmds->cnt; i++)
54 		if (strcmp(cmds->names[i]->name, cmds->names[i-1]->name))
55 			cmds->names[j++] = cmds->names[i];
56 
57 	cmds->cnt = j;
58 }
59 
60 void exclude_cmds(struct cmdnames *cmds, struct cmdnames *excludes)
61 {
62 	size_t ci, cj, ei;
63 	int cmp;
64 
65 	ci = cj = ei = 0;
66 	while (ci < cmds->cnt && ei < excludes->cnt) {
67 		cmp = strcmp(cmds->names[ci]->name, excludes->names[ei]->name);
68 		if (cmp < 0) {
69 			cmds->names[cj++] = cmds->names[ci++];
70 		} else if (cmp == 0) {
71 			ci++;
72 			ei++;
73 		} else if (cmp > 0) {
74 			ei++;
75 		}
76 	}
77 
78 	while (ci < cmds->cnt)
79 		cmds->names[cj++] = cmds->names[ci++];
80 
81 	cmds->cnt = cj;
82 }
83 
84 static void get_term_dimensions(struct winsize *ws)
85 {
86 	char *s = getenv("LINES");
87 
88 	if (s != NULL) {
89 		ws->ws_row = atoi(s);
90 		s = getenv("COLUMNS");
91 		if (s != NULL) {
92 			ws->ws_col = atoi(s);
93 			if (ws->ws_row && ws->ws_col)
94 				return;
95 		}
96 	}
97 #ifdef TIOCGWINSZ
98 	if (ioctl(1, TIOCGWINSZ, ws) == 0 &&
99 	    ws->ws_row && ws->ws_col)
100 		return;
101 #endif
102 	ws->ws_row = 25;
103 	ws->ws_col = 80;
104 }
105 
106 static void pretty_print_string_list(struct cmdnames *cmds, int longest)
107 {
108 	int cols = 1, rows;
109 	int space = longest + 1; /* min 1 SP between words */
110 	struct winsize win;
111 	int max_cols;
112 	int i, j;
113 
114 	get_term_dimensions(&win);
115 	max_cols = win.ws_col - 1; /* don't print *on* the edge */
116 
117 	if (space < max_cols)
118 		cols = max_cols / space;
119 	rows = (cmds->cnt + cols - 1) / cols;
120 
121 	for (i = 0; i < rows; i++) {
122 		printf("  ");
123 
124 		for (j = 0; j < cols; j++) {
125 			unsigned int n = j * rows + i;
126 			unsigned int size = space;
127 
128 			if (n >= cmds->cnt)
129 				break;
130 			if (j == cols-1 || n + rows >= cmds->cnt)
131 				size = 1;
132 			printf("%-*s", size, cmds->names[n]->name);
133 		}
134 		putchar('\n');
135 	}
136 }
137 
138 static int is_executable(const char *name)
139 {
140 	struct stat st;
141 
142 	if (stat(name, &st) || /* stat, not lstat */
143 	    !S_ISREG(st.st_mode))
144 		return 0;
145 
146 	return st.st_mode & S_IXUSR;
147 }
148 
149 static int has_extension(const char *filename, const char *ext)
150 {
151 	size_t len = strlen(filename);
152 	size_t extlen = strlen(ext);
153 
154 	return len > extlen && !memcmp(filename + len - extlen, ext, extlen);
155 }
156 
157 static void list_commands_in_dir(struct cmdnames *cmds,
158 					 const char *path,
159 					 const char *prefix)
160 {
161 	int prefix_len;
162 	DIR *dir = opendir(path);
163 	struct dirent *de;
164 	char *buf = NULL;
165 
166 	if (!dir)
167 		return;
168 	if (!prefix)
169 		prefix = "perf-";
170 	prefix_len = strlen(prefix);
171 
172 	astrcatf(&buf, "%s/", path);
173 
174 	while ((de = readdir(dir)) != NULL) {
175 		int entlen;
176 
177 		if (!strstarts(de->d_name, prefix))
178 			continue;
179 
180 		astrcat(&buf, de->d_name);
181 		if (!is_executable(buf))
182 			continue;
183 
184 		entlen = strlen(de->d_name) - prefix_len;
185 		if (has_extension(de->d_name, ".exe"))
186 			entlen -= 4;
187 
188 		add_cmdname(cmds, de->d_name + prefix_len, entlen);
189 	}
190 	closedir(dir);
191 	free(buf);
192 }
193 
194 void load_command_list(const char *prefix,
195 		struct cmdnames *main_cmds,
196 		struct cmdnames *other_cmds)
197 {
198 	const char *env_path = getenv("PATH");
199 	char *exec_path = get_argv_exec_path();
200 
201 	if (exec_path) {
202 		list_commands_in_dir(main_cmds, exec_path, prefix);
203 		qsort(main_cmds->names, main_cmds->cnt,
204 		      sizeof(*main_cmds->names), cmdname_compare);
205 		uniq(main_cmds);
206 	}
207 
208 	if (env_path) {
209 		char *paths, *path, *colon;
210 		path = paths = strdup(env_path);
211 		while (1) {
212 			if ((colon = strchr(path, ':')))
213 				*colon = 0;
214 			if (!exec_path || strcmp(path, exec_path))
215 				list_commands_in_dir(other_cmds, path, prefix);
216 
217 			if (!colon)
218 				break;
219 			path = colon + 1;
220 		}
221 		free(paths);
222 
223 		qsort(other_cmds->names, other_cmds->cnt,
224 		      sizeof(*other_cmds->names), cmdname_compare);
225 		uniq(other_cmds);
226 	}
227 	free(exec_path);
228 	exclude_cmds(other_cmds, main_cmds);
229 }
230 
231 void list_commands(const char *title, struct cmdnames *main_cmds,
232 		   struct cmdnames *other_cmds)
233 {
234 	unsigned int i, longest = 0;
235 
236 	for (i = 0; i < main_cmds->cnt; i++)
237 		if (longest < main_cmds->names[i]->len)
238 			longest = main_cmds->names[i]->len;
239 	for (i = 0; i < other_cmds->cnt; i++)
240 		if (longest < other_cmds->names[i]->len)
241 			longest = other_cmds->names[i]->len;
242 
243 	if (main_cmds->cnt) {
244 		char *exec_path = get_argv_exec_path();
245 		printf("available %s in '%s'\n", title, exec_path);
246 		printf("----------------");
247 		mput_char('-', strlen(title) + strlen(exec_path));
248 		putchar('\n');
249 		pretty_print_string_list(main_cmds, longest);
250 		putchar('\n');
251 		free(exec_path);
252 	}
253 
254 	if (other_cmds->cnt) {
255 		printf("%s available from elsewhere on your $PATH\n", title);
256 		printf("---------------------------------------");
257 		mput_char('-', strlen(title));
258 		putchar('\n');
259 		pretty_print_string_list(other_cmds, longest);
260 		putchar('\n');
261 	}
262 }
263 
264 int is_in_cmdlist(struct cmdnames *c, const char *s)
265 {
266 	unsigned int i;
267 
268 	for (i = 0; i < c->cnt; i++)
269 		if (!strcmp(s, c->names[i]->name))
270 			return 1;
271 	return 0;
272 }
273