src/basic/string-util.c - systemd-stable - Rivoreo Source Code Repositories

 /***
   This file is part of systemd.

   Copyright 2010 Lennart Poettering

   systemd is free software; you can redistribute it and/or modify it
   under the terms of the GNU Lesser General Public License as published by
   the Free Software Foundation; either version 2.1 of the License, or
   (at your option) any later version.

   systemd is distributed in the hope that it will be useful, but
   WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public License
   along with systemd; If not, see <http://www.gnu.org/licenses/>.
 ***/

 #include <errno.h>
 #include <stdarg.h>
 #include <stdint.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>

 #include "alloc-util.h"
 #include "gunicode.h"
 #include "macro.h"
 #include "string-util.h"
 #include "utf8.h"
 #include "util.h"

 int strcmp_ptr(const char *a, const char *b) {

         /* Like strcmp(), but tries to make sense of NULL pointers */
         if (a && b)
                 return strcmp(a, b);

         if (!a && b)
                 return -1;

         if (a && !b)
                 return 1;

         return 0;
 }

 char* endswith(const char *s, const char *postfix) {
         size_t sl, pl;

         assert(s);
         assert(postfix);

         sl = strlen(s);
         pl = strlen(postfix);

         if (pl == 0)
                 return (char*) s + sl;

         if (sl < pl)
                 return NULL;

         if (memcmp(s + sl - pl, postfix, pl) != 0)
                 return NULL;

         return (char*) s + sl - pl;
 }

 char* endswith_no_case(const char *s, const char *postfix) {
         size_t sl, pl;

         assert(s);
         assert(postfix);

         sl = strlen(s);
         pl = strlen(postfix);

         if (pl == 0)
                 return (char*) s + sl;

         if (sl < pl)
                 return NULL;

         if (strcasecmp(s + sl - pl, postfix) != 0)
                 return NULL;

         return (char*) s + sl - pl;
 }

 char* first_word(const char *s, const char *word) {
         size_t sl, wl;
         const char *p;

         assert(s);
         assert(word);

         /* Checks if the string starts with the specified word, either
          * followed by NUL or by whitespace. Returns a pointer to the
          * NUL or the first character after the whitespace. */

         sl = strlen(s);
         wl = strlen(word);

         if (sl < wl)
                 return NULL;

         if (wl == 0)
                 return (char*) s;

         if (memcmp(s, word, wl) != 0)
                 return NULL;

         p = s + wl;
         if (*p == 0)
                 return (char*) p;

         if (!strchr(WHITESPACE, *p))
                 return NULL;

         p += strspn(p, WHITESPACE);
         return (char*) p;
 }

 static size_t strcspn_escaped(const char *s, const char *reject) {
         bool escaped = false;
         int n;

         for (n=0; s[n]; n++) {
                 if (escaped)
                         escaped = false;
                 else if (s[n] == '\\')
                         escaped = true;
                 else if (strchr(reject, s[n]))
                         break;
         }

         /* if s ends in \, return index of previous char */
         return n - escaped;
 }

 /* Split a string into words. */
 const char* split(const char **state, size_t *l, const char *separator, bool quoted) {
         const char *current;

         current = *state;

         if (!*current) {
                 assert(**state == '\0');
                 return NULL;
         }

         current += strspn(current, separator);
         if (!*current) {
                 *state = current;
                 return NULL;
         }

         if (quoted && strchr("\'\"", *current)) {
                 char quotechars[2] = {*current, '\0'};

                 *l = strcspn_escaped(current + 1, quotechars);
                 if (current[*l + 1] == '\0' || current[*l + 1] != quotechars[0] ||
                     (current[*l + 2] && !strchr(separator, current[*l + 2]))) {
                         /* right quote missing or garbage at the end */
                         *state = current;
                         return NULL;
                 }
                 *state = current++ + *l + 2;
         } else if (quoted) {
                 *l = strcspn_escaped(current, separator);
                 if (current[*l] && !strchr(separator, current[*l])) {
                         /* unfinished escape */
                         *state = current;
                         return NULL;
                 }
                 *state = current + *l;
         } else {
                 *l = strcspn(current, separator);
                 *state = current + *l;
         }

         return current;
 }

 char *strnappend(const char *s, const char *suffix, size_t b) {
         size_t a;
         char *r;

         if (!s && !suffix)
                 return strdup("");

         if (!s)
                 return strndup(suffix, b);

         if (!suffix)
                 return strdup(s);

         assert(s);
         assert(suffix);

         a = strlen(s);
         if (b > ((size_t) -1) - a)
                 return NULL;

         r = new(char, a+b+1);
         if (!r)
                 return NULL;

         memcpy(r, s, a);
         memcpy(r+a, suffix, b);
         r[a+b] = 0;

         return r;
 }

 char *strappend(const char *s, const char *suffix) {
         return strnappend(s, suffix, suffix ? strlen(suffix) : 0);
 }

 char *strjoin_real(const char *x, ...) {
         va_list ap;
         size_t l;
         char *r, *p;

         va_start(ap, x);

         if (x) {
                 l = strlen(x);

                 for (;;) {
                         const char *t;
                         size_t n;

                         t = va_arg(ap, const char *);
                         if (!t)
                                 break;

                         n = strlen(t);
                         if (n > ((size_t) -1) - l) {
                                 va_end(ap);
                                 return NULL;
                         }

                         l += n;
                 }
         } else
                 l = 0;

         va_end(ap);

         r = new(char, l+1);
         if (!r)
                 return NULL;

         if (x) {
                 p = stpcpy(r, x);

                 va_start(ap, x);

                 for (;;) {
                         const char *t;

                         t = va_arg(ap, const char *);
                         if (!t)
                                 break;

                         p = stpcpy(p, t);
                 }

                 va_end(ap);
         } else
                 r[0] = 0;

         return r;
 }

 char *strstrip(char *s) {
         char *e;

         /* Drops trailing whitespace. Modifies the string in
          * place. Returns pointer to first non-space character */

         s += strspn(s, WHITESPACE);

         for (e = strchr(s, 0); e > s; e --)
                 if (!strchr(WHITESPACE, e[-1]))
                         break;

         *e = 0;

         return s;
 }

 char *delete_chars(char *s, const char *bad) {
         char *f, *t;

         /* Drops all whitespace, regardless where in the string */

         for (f = s, t = s; *f; f++) {
                 if (strchr(bad, *f))
                         continue;

                 *(t++) = *f;
         }

         *t = 0;

         return s;
 }

 char *truncate_nl(char *s) {
         assert(s);

         s[strcspn(s, NEWLINE)] = 0;
         return s;
 }

 char ascii_tolower(char x) {

         if (x >= 'A' && x <= 'Z')
                 return x - 'A' + 'a';

         return x;
 }

 char ascii_toupper(char x) {

         if (x >= 'a' && x <= 'z')
                 return x - 'a' + 'A';

         return x;
 }

 char *ascii_strlower(char *t) {
         char *p;

         assert(t);

         for (p = t; *p; p++)
                 *p = ascii_tolower(*p);

         return t;
 }

 char *ascii_strupper(char *t) {
         char *p;

         assert(t);

         for (p = t; *p; p++)
                 *p = ascii_toupper(*p);

         return t;
 }

 char *ascii_strlower_n(char *t, size_t n) {
         size_t i;

         if (n <= 0)
                 return t;

         for (i = 0; i < n; i++)
                 t[i] = ascii_tolower(t[i]);

         return t;
 }

 int ascii_strcasecmp_n(const char *a, const char *b, size_t n) {

         for (; n > 0; a++, b++, n--) {
                 int x, y;

                 x = (int) (uint8_t) ascii_tolower(*a);
                 y = (int) (uint8_t) ascii_tolower(*b);

                 if (x != y)
                         return x - y;
         }

         return 0;
 }

 int ascii_strcasecmp_nn(const char *a, size_t n, const char *b, size_t m) {
         int r;

         r = ascii_strcasecmp_n(a, b, MIN(n, m));
         if (r != 0)
                 return r;

         if (n < m)
                 return -1;
         else if (n > m)
                 return 1;
         else
                 return 0;
 }

 bool chars_intersect(const char *a, const char *b) {
         const char *p;

         /* Returns true if any of the chars in a are in b. */
         for (p = a; *p; p++)
                 if (strchr(b, *p))
                         return true;

         return false;
 }

 bool string_has_cc(const char *p, const char *ok) {
         const char *t;

         assert(p);

         /*
          * Check if a string contains control characters. If 'ok' is
          * non-NULL it may be a string containing additional CCs to be
          * considered OK.
          */

         for (t = p; *t; t++) {
                 if (ok && strchr(ok, *t))
                         continue;

                 if (*t > 0 && *t < ' ')
                         return true;

                 if (*t == 127)
                         return true;
         }

         return false;
 }

 static char *ascii_ellipsize_mem(const char *s, size_t old_length, size_t new_length, unsigned percent) {
         size_t x;
         char *r;

         assert(s);
         assert(percent <= 100);
         assert(new_length >= 3);

         if (old_length <= 3 || old_length <= new_length)
                 return strndup(s, old_length);

         r = new0(char, new_length+3);
         if (!r)
                 return NULL;

         x = (new_length * percent) / 100;

         if (x > new_length - 3)
                 x = new_length - 3;

         memcpy(r, s, x);
         r[x] = 0xe2; /* tri-dot ellipsis: … */
         r[x+1] = 0x80;
         r[x+2] = 0xa6;
         memcpy(r + x + 3,
                s + old_length - (new_length - x - 1),
                new_length - x - 1);

         return r;
 }

 char *ellipsize_mem(const char *s, size_t old_length, size_t new_length, unsigned percent) {
         size_t x;
         char *e;
         const char *i, *j;
         unsigned k, len, len2;
         int r;

         assert(s);
         assert(percent <= 100);
         assert(new_length >= 3);

         /* if no multibyte characters use ascii_ellipsize_mem for speed */
         if (ascii_is_valid(s))
                 return ascii_ellipsize_mem(s, old_length, new_length, percent);

         if (old_length <= 3 || old_length <= new_length)
                 return strndup(s, old_length);

         x = (new_length * percent) / 100;

         if (x > new_length - 3)
                 x = new_length - 3;

         k = 0;
         for (i = s; k < x && i < s + old_length; i = utf8_next_char(i)) {
                 char32_t c;

                 r = utf8_encoded_to_unichar(i, &c);
                 if (r < 0)
                         return NULL;
                 k += unichar_iswide(c) ? 2 : 1;
         }

         if (k > x) /* last character was wide and went over quota */
                 x++;

         for (j = s + old_length; k < new_length && j > i; ) {
                 char32_t c;

                 j = utf8_prev_char(j);
                 r = utf8_encoded_to_unichar(j, &c);
                 if (r < 0)
                         return NULL;
                 k += unichar_iswide(c) ? 2 : 1;
         }
         assert(i <= j);

         /* we don't actually need to ellipsize */
         if (i == j)
                 return memdup(s, old_length + 1);

         /* make space for ellipsis */
         j = utf8_next_char(j);

         len = i - s;
         len2 = s + old_length - j;
         e = new(char, len + 3 + len2 + 1);
         if (!e)
                 return NULL;

         /*
         printf("old_length=%zu new_length=%zu x=%zu len=%u len2=%u k=%u\n",
                old_length, new_length, x, len, len2, k);
         */

         memcpy(e, s, len);
         e[len]   = 0xe2; /* tri-dot ellipsis: … */
         e[len + 1] = 0x80;
         e[len + 2] = 0xa6;

         memcpy(e + len + 3, j, len2 + 1);

         return e;
 }

 char *ellipsize(const char *s, size_t length, unsigned percent) {
         return ellipsize_mem(s, strlen(s), length, percent);
 }

 bool nulstr_contains(const char*nulstr, const char *needle) {
         const char *i;

         if (!nulstr)
                 return false;

         NULSTR_FOREACH(i, nulstr)
                 if (streq(i, needle))
                         return true;

         return false;
 }

 char* strshorten(char *s, size_t l) {
         assert(s);

         if (l < strlen(s))
                 s[l] = 0;

         return s;
 }

 char *strreplace(const char *text, const char *old_string, const char *new_string) {
         const char *f;
         char *t, *r;
         size_t l, old_len, new_len;

         assert(text);
         assert(old_string);
         assert(new_string);

         old_len = strlen(old_string);
         new_len = strlen(new_string);

         l = strlen(text);
         r = new(char, l+1);
         if (!r)
                 return NULL;

         f = text;
         t = r;
         while (*f) {
                 char *a;
                 size_t d, nl;

                 if (!startswith(f, old_string)) {
                         *(t++) = *(f++);
                         continue;
                 }

                 d = t - r;
                 nl = l - old_len + new_len;
                 a = realloc(r, nl + 1);
                 if (!a)
                         goto oom;

                 l = nl;
                 r = a;
                 t = r + d;

                 t = stpcpy(t, new_string);
                 f += old_len;
         }

         *t = 0;
         return r;

 oom:
         return mfree(r);
 }

 char *strip_tab_ansi(char **ibuf, size_t *_isz) {
         const char *i, *begin = NULL;
         enum {
                 STATE_OTHER,
                 STATE_ESCAPE,
                 STATE_BRACKET
         } state = STATE_OTHER;
         char *obuf = NULL;
         size_t osz = 0, isz;
         FILE *f;

         assert(ibuf);
         assert(*ibuf);

         /* Strips ANSI color and replaces TABs by 8 spaces */

         isz = _isz ? *_isz : strlen(*ibuf);

         f = open_memstream(&obuf, &osz);
         if (!f)
                 return NULL;

         for (i = *ibuf; i < *ibuf + isz + 1; i++) {

                 switch (state) {

                 case STATE_OTHER:
                         if (i >= *ibuf + isz) /* EOT */
                                 break;
                         else if (*i == '\x1B')
                                 state = STATE_ESCAPE;
                         else if (*i == '\t')
                                 fputs("        ", f);
                         else
                                 fputc(*i, f);
                         break;

                 case STATE_ESCAPE:
                         if (i >= *ibuf + isz) { /* EOT */
                                 fputc('\x1B', f);
                                 break;
                         } else if (*i == '[') {
                                 state = STATE_BRACKET;
                                 begin = i + 1;
                         } else {
                                 fputc('\x1B', f);
                                 fputc(*i, f);
                                 state = STATE_OTHER;
                         }

                         break;

                 case STATE_BRACKET:

                         if (i >= *ibuf + isz || /* EOT */
                             (!(*i >= '0' && *i <= '9') && *i != ';' && *i != 'm')) {
                                 fputc('\x1B', f);
                                 fputc('[', f);
                                 state = STATE_OTHER;
                                 i = begin-1;
                         } else if (*i == 'm')
                                 state = STATE_OTHER;
                         break;
                 }
         }

         if (ferror(f)) {
                 fclose(f);
                 return mfree(obuf);
         }

         fclose(f);

         free(*ibuf);
         *ibuf = obuf;

         if (_isz)
                 *_isz = osz;

         return obuf;
 }

 char *strextend(char **x, ...) {
         va_list ap;
         size_t f, l;
         char *r, *p;

         assert(x);

         l = f = *x ? strlen(*x) : 0;

         va_start(ap, x);
         for (;;) {
                 const char *t;
                 size_t n;

                 t = va_arg(ap, const char *);
                 if (!t)
                         break;

                 n = strlen(t);
                 if (n > ((size_t) -1) - l) {
                         va_end(ap);
                         return NULL;
                 }

                 l += n;
         }
         va_end(ap);

         r = realloc(*x, l+1);
         if (!r)
                 return NULL;

         p = r + f;

         va_start(ap, x);
         for (;;) {
                 const char *t;

                 t = va_arg(ap, const char *);
                 if (!t)
                         break;

                 p = stpcpy(p, t);
         }
         va_end(ap);

         *p = 0;
         *x = r;

         return r + l;
 }

 char *strrep(const char *s, unsigned n) {
         size_t l;
         char *r, *p;
         unsigned i;

         assert(s);

         l = strlen(s);
         p = r = malloc(l * n + 1);
         if (!r)
                 return NULL;

         for (i = 0; i < n; i++)
                 p = stpcpy(p, s);

         *p = 0;
         return r;
 }

 int split_pair(const char *s, const char *sep, char **l, char **r) {
         char *x, *a, *b;

         assert(s);
         assert(sep);
         assert(l);
         assert(r);

         if (isempty(sep))
                 return -EINVAL;

         x = strstr(s, sep);
         if (!x)
                 return -EINVAL;

         a = strndup(s, x - s);
         if (!a)
                 return -ENOMEM;

         b = strdup(x + strlen(sep));
         if (!b) {
                 free(a);
                 return -ENOMEM;
         }

         *l = a;
         *r = b;

         return 0;
 }

 int free_and_strdup(char **p, const char *s) {
         char *t;

         assert(p);

         /* Replaces a string pointer with an strdup()ed new string,
          * possibly freeing the old one. */

         if (streq_ptr(*p, s))
                 return 0;

         if (s) {
                 t = strdup(s);
                 if (!t)
                         return -ENOMEM;
         } else
                 t = NULL;

         free(*p);
         *p = t;

         return 1;
 }

 #if !HAVE_DECL_EXPLICIT_BZERO
 /*
  * Pointer to memset is volatile so that compiler must de-reference
  * the pointer and can't assume that it points to any function in
  * particular (such as memset, which it then might further "optimize")
  * This approach is inspired by openssl's crypto/mem_clr.c.
  */
 typedef void *(*memset_t)(void *,int,size_t);

 static volatile memset_t memset_func = memset;

 void explicit_bzero(void *p, size_t l) {
         memset_func(p, '\0', l);
 }
 #endif

 char* string_erase(char *x) {
         if (!x)
                 return NULL;

         /* A delicious drop of snake-oil! To be called on memory where
          * we stored passphrases or so, after we used them. */
         explicit_bzero(x, strlen(x));
         return x;
 }

 char *string_free_erase(char *s) {
         return mfree(string_erase(s));
 }

 bool string_is_safe(const char *p) {
         const char *t;

         if (!p)
                 return false;

         for (t = p; *t; t++) {
                 if (*t > 0 && *t < ' ') /* no control characters */
                         return false;

                 if (strchr(QUOTES "\\\x7f", *t))
                         return false;
         }

         return true;
 }
	/***
	This file is part of systemd.

	Copyright 2010 Lennart Poettering

	systemd is free software; you can redistribute it and/or modify it
	under the terms of the GNU Lesser General Public License as published by
	the Free Software Foundation; either version 2.1 of the License, or
	(at your option) any later version.

	systemd is distributed in the hope that it will be useful, but
	WITHOUT ANY WARRANTY; without even the implied warranty of
	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	Lesser General Public License for more details.

	You should have received a copy of the GNU Lesser General Public License
	along with systemd; If not, see <http://www.gnu.org/licenses/>.
	***/

	#include <errno.h>
	#include <stdarg.h>
	#include <stdint.h>
	#include <stdio.h>
	#include <stdlib.h>
	#include <string.h>

	#include "alloc-util.h"
	#include "gunicode.h"
	#include "macro.h"
	#include "string-util.h"
	#include "utf8.h"
	#include "util.h"

	int strcmp_ptr(const char a, const char b) {

	/* Like strcmp(), but tries to make sense of NULL pointers */
	if (a && b)
	return strcmp(a, b);

	if (!a && b)
	return -1;

	if (a && !b)
	return 1;

	return 0;
	}

	char* endswith(const char s, const char postfix) {
	size_t sl, pl;

	assert(s);
	assert(postfix);

	sl = strlen(s);
	pl = strlen(postfix);

	if (pl == 0)
	return (char*) s + sl;

	if (sl < pl)
	return NULL;

	if (memcmp(s + sl - pl, postfix, pl) != 0)
	return NULL;

	return (char*) s + sl - pl;
	}

	char* endswith_no_case(const char s, const char postfix) {
	size_t sl, pl;

	assert(s);
	assert(postfix);

	sl = strlen(s);
	pl = strlen(postfix);

	if (pl == 0)
	return (char*) s + sl;

	if (sl < pl)
	return NULL;

	if (strcasecmp(s + sl - pl, postfix) != 0)
	return NULL;

	return (char*) s + sl - pl;
	}

	char* first_word(const char s, const char word) {
	size_t sl, wl;
	const char *p;

	assert(s);
	assert(word);

	/* Checks if the string starts with the specified word, either
	* followed by NUL or by whitespace. Returns a pointer to the
	* NUL or the first character after the whitespace. */

	sl = strlen(s);
	wl = strlen(word);

	if (sl < wl)
	return NULL;

	if (wl == 0)
	return (char*) s;

	if (memcmp(s, word, wl) != 0)
	return NULL;

	p = s + wl;
	if (*p == 0)
	return (char*) p;

	if (!strchr(WHITESPACE, *p))
	return NULL;

	p += strspn(p, WHITESPACE);
	return (char*) p;
	}

	static size_t strcspn_escaped(const char s, const char reject) {
	bool escaped = false;
	int n;

	for (n=0; s[n]; n++) {
	if (escaped)
	escaped = false;
	else if (s[n] == '\\')
	escaped = true;
	else if (strchr(reject, s[n]))
	break;
	}

	/* if s ends in \, return index of previous char */
	return n - escaped;
	}

	/* Split a string into words. */
	const char* split(const char *state, size_t l, const char *separator, bool quoted) {
	const char *current;

	current = *state;

	if (!*current) {
	assert(**state == '\0');
	return NULL;
	}

	current += strspn(current, separator);
	if (!*current) {
	*state = current;
	return NULL;
	}

	if (quoted && strchr("\'\"", *current)) {
	char quotechars[2] = {*current, '\0'};

	*l = strcspn_escaped(current + 1, quotechars);
	if (current[l + 1] == '\0' \|\| current[l + 1] != quotechars[0] \|\|
	(current[l + 2] && !strchr(separator, current[l + 2]))) {
	/* right quote missing or garbage at the end */
	*state = current;
	return NULL;
	}
	state = current++ + l + 2;
	} else if (quoted) {
	*l = strcspn_escaped(current, separator);
	if (current[l] && !strchr(separator, current[l])) {
	/* unfinished escape */
	*state = current;
	return NULL;
	}
	state = current + l;
	} else {
	*l = strcspn(current, separator);
	state = current + l;
	}

	return current;
	}

	char strnappend(const char s, const char *suffix, size_t b) {
	size_t a;
	char *r;

	if (!s && !suffix)
	return strdup("");

	if (!s)
	return strndup(suffix, b);

	if (!suffix)
	return strdup(s);

	assert(s);
	assert(suffix);

	a = strlen(s);
	if (b > ((size_t) -1) - a)
	return NULL;

	r = new(char, a+b+1);
	if (!r)
	return NULL;

	memcpy(r, s, a);
	memcpy(r+a, suffix, b);
	r[a+b] = 0;

	return r;
	}

	char strappend(const char s, const char *suffix) {
	return strnappend(s, suffix, suffix ? strlen(suffix) : 0);
	}

	char strjoin_real(const char x, ...) {
	va_list ap;
	size_t l;
	char r, p;

	va_start(ap, x);

	if (x) {
	l = strlen(x);

	for (;;) {
	const char *t;
	size_t n;

	t = va_arg(ap, const char *);
	if (!t)
	break;

	n = strlen(t);
	if (n > ((size_t) -1) - l) {
	va_end(ap);
	return NULL;
	}

	l += n;
	}
	} else
	l = 0;

	va_end(ap);

	r = new(char, l+1);
	if (!r)
	return NULL;

	if (x) {
	p = stpcpy(r, x);

	va_start(ap, x);

	for (;;) {
	const char *t;

	t = va_arg(ap, const char *);
	if (!t)
	break;

	p = stpcpy(p, t);
	}

	va_end(ap);
	} else
	r[0] = 0;

	return r;
	}

	char strstrip(char s) {
	char *e;

	/* Drops trailing whitespace. Modifies the string in
	* place. Returns pointer to first non-space character */

	s += strspn(s, WHITESPACE);

	for (e = strchr(s, 0); e > s; e --)
	if (!strchr(WHITESPACE, e[-1]))
	break;

	*e = 0;

	return s;
	}

	char delete_chars(char s, const char *bad) {
	char f, t;

	/* Drops all whitespace, regardless where in the string */

	for (f = s, t = s; *f; f++) {
	if (strchr(bad, *f))
	continue;

	(t++) = f;
	}

	*t = 0;

	return s;
	}

	char truncate_nl(char s) {
	assert(s);

	s[strcspn(s, NEWLINE)] = 0;
	return s;
	}

	char ascii_tolower(char x) {

	if (x >= 'A' && x <= 'Z')
	return x - 'A' + 'a';

	return x;
	}

	char ascii_toupper(char x) {

	if (x >= 'a' && x <= 'z')
	return x - 'a' + 'A';

	return x;
	}

	char ascii_strlower(char t) {
	char *p;

	assert(t);

	for (p = t; *p; p++)
	p = ascii_tolower(p);

	return t;
	}

	char ascii_strupper(char t) {
	char *p;

	assert(t);

	for (p = t; *p; p++)
	p = ascii_toupper(p);

	return t;
	}

	char ascii_strlower_n(char t, size_t n) {
	size_t i;

	if (n <= 0)
	return t;

	for (i = 0; i < n; i++)
	t[i] = ascii_tolower(t[i]);

	return t;
	}

	int ascii_strcasecmp_n(const char a, const char b, size_t n) {

	for (; n > 0; a++, b++, n--) {
	int x, y;

	x = (int) (uint8_t) ascii_tolower(*a);
	y = (int) (uint8_t) ascii_tolower(*b);

	if (x != y)
	return x - y;
	}

	return 0;
	}

	int ascii_strcasecmp_nn(const char a, size_t n, const char b, size_t m) {
	int r;

	r = ascii_strcasecmp_n(a, b, MIN(n, m));
	if (r != 0)
	return r;

	if (n < m)
	return -1;
	else if (n > m)
	return 1;
	else
	return 0;
	}

	bool chars_intersect(const char a, const char b) {
	const char *p;

	/* Returns true if any of the chars in a are in b. */
	for (p = a; *p; p++)
	if (strchr(b, *p))
	return true;

	return false;
	}

	bool string_has_cc(const char p, const char ok) {
	const char *t;

	assert(p);

	/*
	* Check if a string contains control characters. If 'ok' is
	* non-NULL it may be a string containing additional CCs to be
	* considered OK.
	*/

	for (t = p; *t; t++) {
	if (ok && strchr(ok, *t))
	continue;

	if (t > 0 && t < ' ')
	return true;

	if (*t == 127)
	return true;
	}

	return false;
	}

	static char ascii_ellipsize_mem(const char s, size_t old_length, size_t new_length, unsigned percent) {
	size_t x;
	char *r;

	assert(s);
	assert(percent <= 100);
	assert(new_length >= 3);

	if (old_length <= 3 \|\| old_length <= new_length)
	return strndup(s, old_length);

	r = new0(char, new_length+3);
	if (!r)
	return NULL;

	x = (new_length * percent) / 100;

	if (x > new_length - 3)
	x = new_length - 3;

	memcpy(r, s, x);
	r[x] = 0xe2; /* tri-dot ellipsis: … */
	r[x+1] = 0x80;
	r[x+2] = 0xa6;
	memcpy(r + x + 3,
	s + old_length - (new_length - x - 1),
	new_length - x - 1);

	return r;
	}

	char ellipsize_mem(const char s, size_t old_length, size_t new_length, unsigned percent) {
	size_t x;
	char *e;
	const char i, j;
	unsigned k, len, len2;
	int r;

	assert(s);
	assert(percent <= 100);
	assert(new_length >= 3);

	/* if no multibyte characters use ascii_ellipsize_mem for speed */
	if (ascii_is_valid(s))
	return ascii_ellipsize_mem(s, old_length, new_length, percent);

	if (old_length <= 3 \|\| old_length <= new_length)
	return strndup(s, old_length);

	x = (new_length * percent) / 100;

	if (x > new_length - 3)
	x = new_length - 3;

	k = 0;
	for (i = s; k < x && i < s + old_length; i = utf8_next_char(i)) {
	char32_t c;

	r = utf8_encoded_to_unichar(i, &c);
	if (r < 0)
	return NULL;
	k += unichar_iswide(c) ? 2 : 1;
	}

	if (k > x) /* last character was wide and went over quota */
	x++;

	for (j = s + old_length; k < new_length && j > i; ) {
	char32_t c;

	j = utf8_prev_char(j);
	r = utf8_encoded_to_unichar(j, &c);
	if (r < 0)
	return NULL;
	k += unichar_iswide(c) ? 2 : 1;
	}
	assert(i <= j);

	/* we don't actually need to ellipsize */
	if (i == j)
	return memdup(s, old_length + 1);

	/* make space for ellipsis */
	j = utf8_next_char(j);

	len = i - s;
	len2 = s + old_length - j;
	e = new(char, len + 3 + len2 + 1);
	if (!e)
	return NULL;

	/*
	printf("old_length=%zu new_length=%zu x=%zu len=%u len2=%u k=%u\n",
	old_length, new_length, x, len, len2, k);
	*/

	memcpy(e, s, len);
	e[len] = 0xe2; /* tri-dot ellipsis: … */
	e[len + 1] = 0x80;
	e[len + 2] = 0xa6;

	memcpy(e + len + 3, j, len2 + 1);

	return e;
	}

	char ellipsize(const char s, size_t length, unsigned percent) {
	return ellipsize_mem(s, strlen(s), length, percent);
	}

	bool nulstr_contains(const charnulstr, const char needle) {
	const char *i;

	if (!nulstr)
	return false;

	NULSTR_FOREACH(i, nulstr)
	if (streq(i, needle))
	return true;

	return false;
	}

	char* strshorten(char *s, size_t l) {
	assert(s);

	if (l < strlen(s))
	s[l] = 0;

	return s;
	}

	char strreplace(const char text, const char old_string, const char new_string) {
	const char *f;
	char t, r;
	size_t l, old_len, new_len;

	assert(text);
	assert(old_string);
	assert(new_string);

	old_len = strlen(old_string);
	new_len = strlen(new_string);

	l = strlen(text);
	r = new(char, l+1);
	if (!r)
	return NULL;

	f = text;
	t = r;
	while (*f) {
	char *a;
	size_t d, nl;

	if (!startswith(f, old_string)) {
	(t++) = (f++);
	continue;
	}

	d = t - r;
	nl = l - old_len + new_len;
	a = realloc(r, nl + 1);
	if (!a)
	goto oom;

	l = nl;
	r = a;
	t = r + d;

	t = stpcpy(t, new_string);
	f += old_len;
	}

	*t = 0;
	return r;

	oom:
	return mfree(r);
	}

	char strip_tab_ansi(char ibuf, size_t _isz) {
	const char i, begin = NULL;
	enum {
	STATE_OTHER,
	STATE_ESCAPE,
	STATE_BRACKET
	} state = STATE_OTHER;
	char *obuf = NULL;
	size_t osz = 0, isz;
	FILE *f;

	assert(ibuf);
	assert(*ibuf);

	/* Strips ANSI color and replaces TABs by 8 spaces */

	isz = _isz ? _isz : strlen(ibuf);

	f = open_memstream(&obuf, &osz);
	if (!f)
	return NULL;

	for (i = ibuf; i < ibuf + isz + 1; i++) {

	switch (state) {

	case STATE_OTHER:
	if (i >= ibuf + isz) / EOT */
	break;
	else if (*i == '\x1B')
	state = STATE_ESCAPE;
	else if (*i == '\t')
	fputs(" ", f);
	else
	fputc(*i, f);
	break;

	case STATE_ESCAPE:
	if (i >= ibuf + isz) { / EOT */
	fputc('\x1B', f);
	break;
	} else if (*i == '[') {
	state = STATE_BRACKET;
	begin = i + 1;
	} else {
	fputc('\x1B', f);
	fputc(*i, f);
	state = STATE_OTHER;
	}

	break;

	case STATE_BRACKET:

	if (i >= ibuf + isz \|\| / EOT */
	(!(i >= '0' && i <= '9') && i != ';' && i != 'm')) {
	fputc('\x1B', f);
	fputc('[', f);
	state = STATE_OTHER;
	i = begin-1;
	} else if (*i == 'm')
	state = STATE_OTHER;
	break;
	}
	}

	if (ferror(f)) {
	fclose(f);
	return mfree(obuf);
	}

	fclose(f);

	free(*ibuf);
	*ibuf = obuf;

	if (_isz)
	*_isz = osz;

	return obuf;
	}

	char strextend(char *x, ...) {
	va_list ap;
	size_t f, l;
	char r, p;

	assert(x);

	l = f = x ? strlen(x) : 0;

	va_start(ap, x);
	for (;;) {
	const char *t;
	size_t n;

	t = va_arg(ap, const char *);
	if (!t)
	break;

	n = strlen(t);
	if (n > ((size_t) -1) - l) {
	va_end(ap);
	return NULL;
	}

	l += n;
	}
	va_end(ap);

	r = realloc(*x, l+1);
	if (!r)
	return NULL;

	p = r + f;

	va_start(ap, x);
	for (;;) {
	const char *t;

	t = va_arg(ap, const char *);
	if (!t)
	break;

	p = stpcpy(p, t);
	}
	va_end(ap);

	*p = 0;
	*x = r;

	return r + l;
	}

	char strrep(const char s, unsigned n) {
	size_t l;
	char r, p;
	unsigned i;

	assert(s);

	l = strlen(s);
	p = r = malloc(l * n + 1);
	if (!r)
	return NULL;

	for (i = 0; i < n; i++)
	p = stpcpy(p, s);

	*p = 0;
	return r;
	}

	int split_pair(const char s, const char sep, char l, char r) {
	char x, a, *b;

	assert(s);
	assert(sep);
	assert(l);
	assert(r);

	if (isempty(sep))
	return -EINVAL;

	x = strstr(s, sep);
	if (!x)
	return -EINVAL;

	a = strndup(s, x - s);
	if (!a)
	return -ENOMEM;

	b = strdup(x + strlen(sep));
	if (!b) {
	free(a);
	return -ENOMEM;
	}

	*l = a;
	*r = b;

	return 0;
	}

	int free_and_strdup(char *p, const char s) {
	char *t;

	assert(p);

	/* Replaces a string pointer with an strdup()ed new string,
	* possibly freeing the old one. */

	if (streq_ptr(*p, s))
	return 0;

	if (s) {
	t = strdup(s);
	if (!t)
	return -ENOMEM;
	} else
	t = NULL;

	free(*p);
	*p = t;

	return 1;
	}

	#if !HAVE_DECL_EXPLICIT_BZERO
	/*
	* Pointer to memset is volatile so that compiler must de-reference
	* the pointer and can't assume that it points to any function in
	* particular (such as memset, which it then might further "optimize")
	* This approach is inspired by openssl's crypto/mem_clr.c.
	*/
	typedef void (memset_t)(void *,int,size_t);

	static volatile memset_t memset_func = memset;

	void explicit_bzero(void *p, size_t l) {
	memset_func(p, '\0', l);
	}
	#endif

	char* string_erase(char *x) {
	if (!x)
	return NULL;

	/* A delicious drop of snake-oil! To be called on memory where
	* we stored passphrases or so, after we used them. */
	explicit_bzero(x, strlen(x));
	return x;
	}

	char string_free_erase(char s) {
	return mfree(string_erase(s));
	}

	bool string_is_safe(const char *p) {
	const char *t;

	if (!p)
	return false;

	for (t = p; *t; t++) {
	if (t > 0 && t < ' ') /* no control characters */
	return false;

	if (strchr(QUOTES "\\\x7f", *t))
	return false;
	}

	return true;
	}