1 /* Licensed under GPLv2+ - see LICENSE file for details */
2 #include <ccan/opt/opt.h>
5 #include <sys/termios.h> /* Required on Solaris for struct winsize */
7 #include <sys/unistd.h> /* Required on Solaris for ioctl */
14 /* We only use this for pointer comparisons. */
15 const char opt_hidden[1];
17 #define MIN_DESC_WIDTH 40
18 #define MIN_TOTAL_WIDTH 50
20 static unsigned int get_columns(void)
23 const char *env = getenv("COLUMNS");
32 if (ioctl(0, TIOCGWINSZ, &w) != -1)
42 /* Return number of chars of words to put on this line.
43 * Prefix is set to number to skip at start, maxlen is max width, returns
44 * length (after prefix) to put on this line.
45 * start is set if we start a new line in the source description. */
46 static size_t consume_words(const char *words, size_t maxlen, size_t *prefix,
51 /* Always swollow leading whitespace. */
52 *prefix = strspn(words, " \n");
55 /* Leading whitespace at start of line means literal. */
56 if (*start && *prefix) {
57 oldlen = strcspn(words, "\n");
59 /* Use at least one word, even if it takes us over maxlen. */
60 oldlen = len = strcspn(words, " ");
61 while (len <= maxlen) {
63 len += strspn(words+len, " ");
64 if (words[len] == '\n')
66 len += strcspn(words+len, " \n");
72 *start = (words[oldlen - 1] == '\n');
76 static char *add_str_len(char *base, size_t *len, size_t *max,
77 const char *str, size_t slen)
79 if (slen >= *max - *len)
80 base = opt_alloc.realloc(base, *max = (*max * 2 + slen + 1));
81 memcpy(base + *len, str, slen);
86 static char *add_str(char *base, size_t *len, size_t *max, const char *str)
88 return add_str_len(base, len, max, str, strlen(str));
91 static char *add_indent(char *base, size_t *len, size_t *max, size_t indent)
93 if (indent >= *max - *len)
94 base = opt_alloc.realloc(base, *max = (*max * 2 + indent + 1));
95 memset(base + *len, ' ', indent);
100 static char *add_desc(char *base, size_t *len, size_t *max,
101 unsigned int indent, unsigned int width,
102 const struct opt_table *opt)
104 size_t off, prefix, l;
106 bool same_line = false, start = true;
108 base = add_str(base, len, max, opt->names);
109 off = strlen(opt->names);
110 if (opt->type == OPT_HASARG
111 && !strchr(opt->names, ' ')
112 && !strchr(opt->names, '=')) {
113 base = add_str(base, len, max, " <arg>");
114 off += strlen(" <arg>");
117 /* Do we start description on next line? */
118 if (off + 2 > indent) {
119 base = add_str(base, len, max, "\n");
122 base = add_indent(base, len, max, indent - off);
127 /* Indent description. */
129 while ((l = consume_words(p, width - indent, &prefix, &start)) != 0) {
131 base = add_indent(base, len, max, indent);
133 base = add_str_len(base, len, max, p, l);
134 base = add_str(base, len, max, "\n");
140 /* Empty description? Make it match normal case. */
142 base = add_str(base, len, max, "\n");
145 char buf[OPT_SHOW_LEN + sizeof("...")];
146 strcpy(buf + OPT_SHOW_LEN, "...");
147 opt->show(buf, opt->u.arg);
149 /* If it doesn't fit on this line, indent. */
150 if (off + strlen(" (default: ") + strlen(buf) + strlen(")")
152 base = add_indent(base, len, max, indent);
158 base = add_str(base, len, max, " (default: ");
159 base = add_str(base, len, max, buf);
160 base = add_str(base, len, max, ")\n");
165 char *opt_usage(const char *argv0, const char *extra)
168 size_t max, len, width, indent;
171 width = get_columns();
172 if (width < MIN_TOTAL_WIDTH)
173 width = MIN_TOTAL_WIDTH;
175 /* Figure out longest option. */
177 for (i = 0; i < opt_count; i++) {
179 if (opt_table[i].desc == opt_hidden)
181 if (opt_table[i].type == OPT_SUBTABLE)
183 l = strlen(opt_table[i].names);
184 if (opt_table[i].type == OPT_HASARG
185 && !strchr(opt_table[i].names, ' ')
186 && !strchr(opt_table[i].names, '='))
187 l += strlen(" <arg>");
192 /* Now we know how much to indent */
193 if (indent + MIN_DESC_WIDTH > width)
194 indent = width - MIN_DESC_WIDTH;
199 ret = add_str(ret, &len, &max, "Usage: ");
200 ret = add_str(ret, &len, &max, argv0);
202 /* Find usage message from among registered options if necessary. */
205 for (i = 0; i < opt_count; i++) {
206 if (opt_table[i].cb == (void *)opt_usage_and_exit
207 && opt_table[i].u.carg) {
208 extra = opt_table[i].u.carg;
213 ret = add_str(ret, &len, &max, " ");
214 ret = add_str(ret, &len, &max, extra);
215 ret = add_str(ret, &len, &max, "\n");
217 for (i = 0; i < opt_count; i++) {
218 if (opt_table[i].desc == opt_hidden)
220 if (opt_table[i].type == OPT_SUBTABLE) {
221 ret = add_str(ret, &len, &max, opt_table[i].desc);
222 ret = add_str(ret, &len, &max, ":\n");
225 ret = add_desc(ret, &len, &max, indent, width, &opt_table[i]);