xref: /openbmc/linux/tools/lib/subcmd/help.c (revision ac3cb6de)
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 = j = 1; i < cmds->cnt; i++)
56 		if (strcmp(cmds->names[i]->name, cmds->names[i-1]->name))
57 			cmds->names[j++] = cmds->names[i];
58 
59 	cmds->cnt = j;
60 }
61 
62 void exclude_cmds(struct cmdnames *cmds, struct cmdnames *excludes)
63 {
64 	size_t ci, cj, ei;
65 	int cmp;
66 
67 	ci = cj = ei = 0;
68 	while (ci < cmds->cnt && ei < excludes->cnt) {
69 		cmp = strcmp(cmds->names[ci]->name, excludes->names[ei]->name);
70 		if (cmp < 0) {
71 			if (ci == cj) {
72 				ci++;
73 				cj++;
74 			} else {
75 				zfree(&cmds->names[cj]);
76 				cmds->names[cj++] = cmds->names[ci++];
77 			}
78 		} else if (cmp == 0) {
79 			ci++;
80 			ei++;
81 		} else if (cmp > 0) {
82 			ei++;
83 		}
84 	}
85 	if (ci != cj) {
86 		while (ci < cmds->cnt) {
87 			zfree(&cmds->names[cj]);
88 			cmds->names[cj++] = cmds->names[ci++];
89 		}
90 	}
91 	for (ci = cj; ci < cmds->cnt; ci++)
92 		zfree(&cmds->names[ci]);
93 	cmds->cnt = cj;
94 }
95 
96 static void get_term_dimensions(struct winsize *ws)
97 {
98 	char *s = getenv("LINES");
99 
100 	if (s != NULL) {
101 		ws->ws_row = atoi(s);
102 		s = getenv("COLUMNS");
103 		if (s != NULL) {
104 			ws->ws_col = atoi(s);
105 			if (ws->ws_row && ws->ws_col)
106 				return;
107 		}
108 	}
109 #ifdef TIOCGWINSZ
110 	if (ioctl(1, TIOCGWINSZ, ws) == 0 &&
111 	    ws->ws_row && ws->ws_col)
112 		return;
113 #endif
114 	ws->ws_row = 25;
115 	ws->ws_col = 80;
116 }
117 
118 static void pretty_print_string_list(struct cmdnames *cmds, int longest)
119 {
120 	int cols = 1, rows;
121 	int space = longest + 1; /* min 1 SP between words */
122 	struct winsize win;
123 	int max_cols;
124 	int i, j;
125 
126 	get_term_dimensions(&win);
127 	max_cols = win.ws_col - 1; /* don't print *on* the edge */
128 
129 	if (space < max_cols)
130 		cols = max_cols / space;
131 	rows = (cmds->cnt + cols - 1) / cols;
132 
133 	for (i = 0; i < rows; i++) {
134 		printf("  ");
135 
136 		for (j = 0; j < cols; j++) {
137 			unsigned int n = j * rows + i;
138 			unsigned int size = space;
139 
140 			if (n >= cmds->cnt)
141 				break;
142 			if (j == cols-1 || n + rows >= cmds->cnt)
143 				size = 1;
144 			printf("%-*s", size, cmds->names[n]->name);
145 		}
146 		putchar('\n');
147 	}
148 }
149 
150 static int is_executable(const char *name)
151 {
152 	struct stat st;
153 
154 	if (stat(name, &st) || /* stat, not lstat */
155 	    !S_ISREG(st.st_mode))
156 		return 0;
157 
158 	return st.st_mode & S_IXUSR;
159 }
160 
161 static int has_extension(const char *filename, const char *ext)
162 {
163 	size_t len = strlen(filename);
164 	size_t extlen = strlen(ext);
165 
166 	return len > extlen && !memcmp(filename + len - extlen, ext, extlen);
167 }
168 
169 static void list_commands_in_dir(struct cmdnames *cmds,
170 					 const char *path,
171 					 const char *prefix)
172 {
173 	int prefix_len;
174 	DIR *dir = opendir(path);
175 	struct dirent *de;
176 	char *buf = NULL;
177 
178 	if (!dir)
179 		return;
180 	if (!prefix)
181 		prefix = "perf-";
182 	prefix_len = strlen(prefix);
183 
184 	astrcatf(&buf, "%s/", path);
185 
186 	while ((de = readdir(dir)) != NULL) {
187 		int entlen;
188 
189 		if (!strstarts(de->d_name, prefix))
190 			continue;
191 
192 		astrcat(&buf, de->d_name);
193 		if (!is_executable(buf))
194 			continue;
195 
196 		entlen = strlen(de->d_name) - prefix_len;
197 		if (has_extension(de->d_name, ".exe"))
198 			entlen -= 4;
199 
200 		add_cmdname(cmds, de->d_name + prefix_len, entlen);
201 	}
202 	closedir(dir);
203 	free(buf);
204 }
205 
206 void load_command_list(const char *prefix,
207 		struct cmdnames *main_cmds,
208 		struct cmdnames *other_cmds)
209 {
210 	const char *env_path = getenv("PATH");
211 	char *exec_path = get_argv_exec_path();
212 
213 	if (exec_path) {
214 		list_commands_in_dir(main_cmds, exec_path, prefix);
215 		qsort(main_cmds->names, main_cmds->cnt,
216 		      sizeof(*main_cmds->names), cmdname_compare);
217 		uniq(main_cmds);
218 	}
219 
220 	if (env_path) {
221 		char *paths, *path, *colon;
222 		path = paths = strdup(env_path);
223 		while (1) {
224 			if ((colon = strchr(path, ':')))
225 				*colon = 0;
226 			if (!exec_path || strcmp(path, exec_path))
227 				list_commands_in_dir(other_cmds, path, prefix);
228 
229 			if (!colon)
230 				break;
231 			path = colon + 1;
232 		}
233 		free(paths);
234 
235 		qsort(other_cmds->names, other_cmds->cnt,
236 		      sizeof(*other_cmds->names), cmdname_compare);
237 		uniq(other_cmds);
238 	}
239 	free(exec_path);
240 	exclude_cmds(other_cmds, main_cmds);
241 }
242 
243 void list_commands(const char *title, struct cmdnames *main_cmds,
244 		   struct cmdnames *other_cmds)
245 {
246 	unsigned int i, longest = 0;
247 
248 	for (i = 0; i < main_cmds->cnt; i++)
249 		if (longest < main_cmds->names[i]->len)
250 			longest = main_cmds->names[i]->len;
251 	for (i = 0; i < other_cmds->cnt; i++)
252 		if (longest < other_cmds->names[i]->len)
253 			longest = other_cmds->names[i]->len;
254 
255 	if (main_cmds->cnt) {
256 		char *exec_path = get_argv_exec_path();
257 		printf("available %s in '%s'\n", title, exec_path);
258 		printf("----------------");
259 		mput_char('-', strlen(title) + strlen(exec_path));
260 		putchar('\n');
261 		pretty_print_string_list(main_cmds, longest);
262 		putchar('\n');
263 		free(exec_path);
264 	}
265 
266 	if (other_cmds->cnt) {
267 		printf("%s available from elsewhere on your $PATH\n", title);
268 		printf("---------------------------------------");
269 		mput_char('-', strlen(title));
270 		putchar('\n');
271 		pretty_print_string_list(other_cmds, longest);
272 		putchar('\n');
273 	}
274 }
275 
276 int is_in_cmdlist(struct cmdnames *c, const char *s)
277 {
278 	unsigned int i;
279 
280 	for (i = 0; i < c->cnt; i++)
281 		if (!strcmp(s, c->names[i]->name))
282 			return 1;
283 	return 0;
284 }
285