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/* Licensed under GPLv2+ - see LICENSE file for details */
#include <ccan/opt/opt.h>
#if HAVE_SYS_TERMIOS_H
#include <sys/ioctl.h>
#include <sys/termios.h> /* Required on Solaris for struct winsize */
#endif
#include <sys/unistd.h> /* Required on Solaris for ioctl */
#include <string.h>
#include <stdlib.h>
#include <stdio.h>
#include <stdint.h>
#include <stdarg.h>
#include "private.h"
/* We only use this for pointer comparisons. */
const char opt_hidden[1];
#define MIN_DESC_WIDTH 40
#define MIN_TOTAL_WIDTH 50
static unsigned int get_columns(void)
{
int ws_col = 0;
const char *env = getenv("COLUMNS");
if (env)
ws_col = atoi(env);
#ifdef TIOCGWINSZ
if (!ws_col)
{
struct winsize w;
if (ioctl(0, TIOCGWINSZ, &w) != -1)
ws_col = w.ws_col;
}
#endif
if (!ws_col)
ws_col = 80;
return ws_col;
}
/* Return number of chars of words to put on this line.
* Prefix is set to number to skip at start, maxlen is max width, returns
* length (after prefix) to put on this line.
* start is set if we start a new line in the source description. */
static size_t consume_words(const char *words, size_t maxlen, size_t *prefix,
bool *start)
{
size_t oldlen, len;
/* Always swollow leading whitespace. */
*prefix = strspn(words, " \n");
words += *prefix;
/* Leading whitespace at start of line means literal. */
if (*start && *prefix) {
oldlen = strcspn(words, "\n");
} else {
/* Use at least one word, even if it takes us over maxlen. */
oldlen = len = strcspn(words, " ");
while (len <= maxlen) {
oldlen = len;
len += strspn(words+len, " ");
if (words[len] == '\n')
break;
len += strcspn(words+len, " \n");
if (len == oldlen)
break;
}
}
*start = (words[oldlen - 1] == '\n');
return oldlen;
}
static char *add_str_len(char *base, size_t *len, size_t *max,
const char *str, size_t slen)
{
if (slen >= *max - *len)
base = opt_alloc.realloc(base, *max = (*max * 2 + slen + 1));
memcpy(base + *len, str, slen);
*len += slen;
return base;
}
static char *add_str(char *base, size_t *len, size_t *max, const char *str)
{
return add_str_len(base, len, max, str, strlen(str));
}
static char *add_indent(char *base, size_t *len, size_t *max, size_t indent)
{
if (indent >= *max - *len)
base = opt_alloc.realloc(base, *max = (*max * 2 + indent + 1));
memset(base + *len, ' ', indent);
*len += indent;
return base;
}
static char *add_desc(char *base, size_t *len, size_t *max,
unsigned int indent, unsigned int width,
const struct opt_table *opt)
{
size_t off, prefix, l;
const char *p;
bool same_line = false, start = true;
base = add_str(base, len, max, opt->names);
off = strlen(opt->names);
if (opt->type == OPT_HASARG
&& !strchr(opt->names, ' ')
&& !strchr(opt->names, '=')) {
base = add_str(base, len, max, " <arg>");
off += strlen(" <arg>");
}
/* Do we start description on next line? */
if (off + 2 > indent) {
base = add_str(base, len, max, "\n");
off = 0;
} else {
base = add_indent(base, len, max, indent - off);
off = indent;
same_line = true;
}
/* Indent description. */
p = opt->desc;
while ((l = consume_words(p, width - indent, &prefix, &start)) != 0) {
if (!same_line)
base = add_indent(base, len, max, indent);
p += prefix;
base = add_str_len(base, len, max, p, l);
base = add_str(base, len, max, "\n");
off = indent + l;
p += l;
same_line = false;
}
/* Empty description? Make it match normal case. */
if (same_line)
base = add_str(base, len, max, "\n");
if (opt->show) {
char buf[OPT_SHOW_LEN + sizeof("...")];
strcpy(buf + OPT_SHOW_LEN, "...");
opt->show(buf, opt->u.arg);
/* If it doesn't fit on this line, indent. */
if (off + strlen(" (default: ") + strlen(buf) + strlen(")")
> width) {
base = add_indent(base, len, max, indent);
} else {
/* Remove \n. */
(*len)--;
}
base = add_str(base, len, max, " (default: ");
base = add_str(base, len, max, buf);
base = add_str(base, len, max, ")\n");
}
return base;
}
char *opt_usage(const char *argv0, const char *extra)
{
unsigned int i;
size_t max, len, width, indent;
char *ret;
width = get_columns();
if (width < MIN_TOTAL_WIDTH)
width = MIN_TOTAL_WIDTH;
/* Figure out longest option. */
indent = 0;
for (i = 0; i < opt_count; i++) {
size_t l;
if (opt_table[i].desc == opt_hidden)
continue;
if (opt_table[i].type == OPT_SUBTABLE)
continue;
l = strlen(opt_table[i].names);
if (opt_table[i].type == OPT_HASARG
&& !strchr(opt_table[i].names, ' ')
&& !strchr(opt_table[i].names, '='))
l += strlen(" <arg>");
if (l + 2 > indent)
indent = l + 2;
}
/* Now we know how much to indent */
if (indent + MIN_DESC_WIDTH > width)
indent = width - MIN_DESC_WIDTH;
len = max = 0;
ret = NULL;
ret = add_str(ret, &len, &max, "Usage: ");
ret = add_str(ret, &len, &max, argv0);
/* Find usage message from among registered options if necessary. */
if (!extra) {
extra = "";
for (i = 0; i < opt_count; i++) {
if (opt_table[i].cb == (void *)opt_usage_and_exit
&& opt_table[i].u.carg) {
extra = opt_table[i].u.carg;
break;
}
}
}
ret = add_str(ret, &len, &max, " ");
ret = add_str(ret, &len, &max, extra);
ret = add_str(ret, &len, &max, "\n");
for (i = 0; i < opt_count; i++) {
if (opt_table[i].desc == opt_hidden)
continue;
if (opt_table[i].type == OPT_SUBTABLE) {
ret = add_str(ret, &len, &max, opt_table[i].desc);
ret = add_str(ret, &len, &max, ":\n");
continue;
}
ret = add_desc(ret, &len, &max, indent, width, &opt_table[i]);
}
ret[len] = '\0';
return ret;
}
void opt_usage_exit_fail(const char *msg, ...)
{
va_list ap;
if (opt_argv0)
fprintf(stderr, "%s: ", opt_argv0);
va_start(ap, msg);
vfprintf(stderr, msg, ap);
va_end(ap);
fprintf(stderr, "\n%s",
opt_usage(opt_argv0 ? opt_argv0 : "<program>", NULL));
exit(1);
}
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