xref: /linux/tools/lib/subcmd/help.c (revision 7821fa101eab529521aa4b724bf708149d70820c)
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