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systemd/src/basic/string-util.c

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/* SPDX-License-Identifier: LGPL-2.1-or-later */
#include <errno.h>
#include <stdarg.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include "alloc-util.h"
#include "escape.h"
#include "extract-word.h"
#include "fd-util.h"
#include "fileio.h"
#include "gunicode.h"
#include "locale-util.h"
#include "macro.h"
#include "memory-util.h"
#include "memstream-util.h"
#include "path-util.h"
#include "string-util.h"
#include "strv.h"
#include "terminal-util.h"
#include "utf8.h"
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;
}
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_MAX - 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 *strjoin_real(const char *x, ...) {
va_list ap;
size_t l = 1;
char *r, *p;
va_start(ap, x);
for (const char *t = x; t; t = va_arg(ap, const char *)) {
size_t n;
n = strlen(t);
if (n > SIZE_MAX - l) {
va_end(ap);
return NULL;
}
l += n;
}
va_end(ap);
p = r = new(char, l);
if (!r)
return NULL;
va_start(ap, x);
for (const char *t = x; t; t = va_arg(ap, const char *))
p = stpcpy(p, t);
va_end(ap);
*p = 0;
return r;
}
char *strstrip(char *s) {
if (!s)
return NULL;
/* Drops trailing whitespace. Modifies the string in place. Returns pointer to first non-space character */
return delete_trailing_chars(skip_leading_chars(s, WHITESPACE), WHITESPACE);
}
char *delete_chars(char *s, const char *bad) {
char *f, *t;
/* Drops all specified bad characters, regardless where in the string */
if (!s)
return NULL;
if (!bad)
bad = WHITESPACE;
for (f = s, t = s; *f; f++) {
if (strchr(bad, *f))
continue;
*(t++) = *f;
}
*t = 0;
return s;
}
char *delete_trailing_chars(char *s, const char *bad) {
char *c = s;
/* Drops all specified bad characters, at the end of the string */
if (!s)
return NULL;
if (!bad)
bad = WHITESPACE;
for (char *p = s; *p; p++)
if (!strchr(bad, *p))
c = p + 1;
*c = 0;
return s;
}
char *truncate_nl_full(char *s, size_t *ret_len) {
size_t n;
assert(s);
n = strcspn(s, NEWLINE);
s[n] = '\0';
if (ret_len)
*ret_len = n;
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) {
assert(t);
for (char *p = t; *p; p++)
*p = ascii_tolower(*p);
return t;
}
char *ascii_strupper(char *t) {
assert(t);
for (char *p = t; *p; p++)
*p = ascii_toupper(*p);
return t;
}
char *ascii_strlower_n(char *t, size_t n) {
if (n <= 0)
return t;
for (size_t 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;
return CMP(n, m);
}
bool chars_intersect(const char *a, const char *b) {
/* Returns true if any of the chars in a are in b. */
for (const char *p = a; *p; p++)
if (strchr(b, *p))
return true;
return false;
}
bool string_has_cc(const char *p, const char *ok) {
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 (const char *t = p; *t; t++) {
if (ok && strchr(ok, *t))
continue;
if (char_is_cc(*t))
return true;
}
return false;
}
static int write_ellipsis(char *buf, bool unicode) {
if (unicode || is_locale_utf8()) {
buf[0] = 0xe2; /* tri-dot ellipsis: … */
buf[1] = 0x80;
buf[2] = 0xa6;
} else {
buf[0] = '.';
buf[1] = '.';
buf[2] = '.';
}
return 3;
}
static size_t ansi_sequence_length(const char *s, size_t len) {
assert(s);
if (len < 2)
return 0;
if (s[0] != 0x1B) /* ASCII 27, aka ESC, aka Ctrl-[ */
return 0; /* Not the start of a sequence */
if (s[1] == 0x5B) { /* [, start of CSI sequence */
size_t i = 2;
if (i == len)
return 0;
while (s[i] >= 0x30 && s[i] <= 0x3F) /* Parameter bytes */
if (++i == len)
return 0;
while (s[i] >= 0x20 && s[i] <= 0x2F) /* Intermediate bytes */
if (++i == len)
return 0;
if (s[i] >= 0x40 && s[i] <= 0x7E) /* Final byte */
return i + 1;
return 0; /* Bad sequence */
} else if (s[1] >= 0x40 && s[1] <= 0x5F) /* other non-CSI Fe sequence */
return 2;
return 0; /* Bad escape? */
}
static bool string_has_ansi_sequence(const char *s, size_t len) {
const char *t = s;
while ((t = memchr(s, 0x1B, len - (t - s))))
if (ansi_sequence_length(t, len - (t - s)) > 0)
return true;
return false;
}
static size_t previous_ansi_sequence(const char *s, size_t length, const char **ret_where) {
/* Locate the previous ANSI sequence and save its start in *ret_where and return length. */
for (size_t i = length - 2; i > 0; i--) { /* -2 because at least two bytes are needed */
size_t slen = ansi_sequence_length(s + (i - 1), length - (i - 1));
if (slen == 0)
continue;
*ret_where = s + (i - 1);
return slen;
}
*ret_where = NULL;
return 0;
}
static char *ascii_ellipsize_mem(const char *s, size_t old_length, size_t new_length, unsigned percent) {
size_t x, need_space, suffix_len;
char *t;
assert(s);
assert(percent <= 100);
assert(new_length != SIZE_MAX);
if (old_length <= new_length)
return strndup(s, old_length);
/* Special case short ellipsations */
switch (new_length) {
case 0:
return strdup("");
case 1:
if (is_locale_utf8())
return strdup("…");
else
return strdup(".");
case 2:
if (!is_locale_utf8())
return strdup("..");
break;
default:
break;
}
/* Calculate how much space the ellipsis will take up. If we are in UTF-8 mode we only need space for one
* character ("…"), otherwise for three characters ("..."). Note that in both cases we need 3 bytes of storage,
* either for the UTF-8 encoded character or for three ASCII characters. */
need_space = is_locale_utf8() ? 1 : 3;
t = new(char, new_length+3);
if (!t)
return NULL;
assert(new_length >= need_space);
x = ((new_length - need_space) * percent + 50) / 100;
assert(x <= new_length - need_space);
memcpy(t, s, x);
write_ellipsis(t + x, false);
suffix_len = new_length - x - need_space;
memcpy(t + x + 3, s + old_length - suffix_len, suffix_len);
*(t + x + 3 + suffix_len) = '\0';
return t;
}
char *ellipsize_mem(const char *s, size_t old_length, size_t new_length, unsigned percent) {
size_t x, k, len, len2;
const char *i, *j;
int r;
/* Note that 'old_length' refers to bytes in the string, while 'new_length' refers to character cells taken up
* on screen. This distinction doesn't matter for ASCII strings, but it does matter for non-ASCII UTF-8
* strings.
*
* Ellipsation is done in a locale-dependent way:
* 1. If the string passed in is fully ASCII and the current locale is not UTF-8, three dots are used ("...")
* 2. Otherwise, a unicode ellipsis is used ("…")
*
* In other words: you'll get a unicode ellipsis as soon as either the string contains non-ASCII characters or
* the current locale is UTF-8.
*/
assert(s);
assert(percent <= 100);
if (new_length == SIZE_MAX)
return strndup(s, old_length);
if (new_length == 0)
return strdup("");
bool has_ansi_seq = string_has_ansi_sequence(s, old_length);
/* If no multibyte characters or ANSI sequences, use ascii_ellipsize_mem for speed */
if (!has_ansi_seq && ascii_is_valid_n(s, old_length))
return ascii_ellipsize_mem(s, old_length, new_length, percent);
x = (new_length - 1) * percent / 100;
assert(x <= new_length - 1);
k = 0;
for (i = s; i < s + old_length; ) {
size_t slen = has_ansi_seq ? ansi_sequence_length(i, old_length - (i - s)) : 0;
if (slen > 0) {
i += slen;
continue; /* ANSI sequences don't take up any space in output */
}
char32_t c;
r = utf8_encoded_to_unichar(i, &c);
if (r < 0)
return NULL;
int w = unichar_iswide(c) ? 2 : 1;
if (k + w > x)
break;
k += w;
i += r;
}
const char *ansi_start = s + old_length;
size_t ansi_len = 0;
for (const char *t = j = s + old_length; t > i && k < new_length; ) {
char32_t c;
int w;
const char *tt;
if (has_ansi_seq && ansi_start >= t)
/* Figure out the previous ANSI sequence, if any */
ansi_len = previous_ansi_sequence(s, t - s, &ansi_start);
/* If the sequence extends all the way to the current position, skip it. */
if (has_ansi_seq && ansi_len > 0 && ansi_start + ansi_len == t) {
t = ansi_start;
continue;
}
tt = utf8_prev_char(t);
r = utf8_encoded_to_unichar(tt, &c);
if (r < 0)
return NULL;
w = unichar_iswide(c) ? 2 : 1;
if (k + w > new_length)
break;
k += w;
j = t = tt; /* j should always point to the first "real" character */
}
/* We don't actually need to ellipsize */
if (i >= j)
return memdup_suffix0(s, old_length);
if (k >= new_length) {
/* Make space for ellipsis, if required and possible. We know that the edge character is not
* part of an ANSI sequence (because then we'd skip it). If the last character we looked at
* was wide, we don't need to make space. */
if (j < s + old_length)
j = utf8_next_char(j);
else if (i > s)
i = utf8_prev_char(i);
}
len = i - s;
len2 = s + old_length - j;
/* If we have ANSI, allow the same length as the source string + ellipsis. It'd be too involved to
* figure out what exact space is needed. Strings with ANSI sequences are most likely to be fairly
* short anyway. */
size_t alloc_len = has_ansi_seq ? old_length + 3 + 1 : len + 3 + len2 + 1;
char *e = new(char, alloc_len);
if (!e)
return NULL;
/*
printf("old_length=%zu new_length=%zu x=%zu len=%zu len2=%zu k=%zu\n",
old_length, new_length, x, len, len2, k);
*/
memcpy_safe(e, s, len);
write_ellipsis(e + len, true);
char *dst = e + len + 3;
if (has_ansi_seq)
/* Copy over any ANSI sequences in full */
for (const char *p = s + len; p < j; ) {
size_t slen = ansi_sequence_length(p, j - p);
if (slen > 0) {
dst = mempcpy(dst, p, slen);
p += slen;
} else
p = utf8_next_char(p);
}
memcpy_safe(dst, j, len2);
dst[len2] = '\0';
return e;
}
char *cellescape(char *buf, size_t len, const char *s) {
/* Escape and ellipsize s into buffer buf of size len. Only non-control ASCII
* characters are copied as they are, everything else is escaped. The result
* is different then if escaping and ellipsization was performed in two
* separate steps, because each sequence is either stored in full or skipped.
*
* This function should be used for logging about strings which expected to
* be plain ASCII in a safe way.
*
* An ellipsis will be used if s is too long. It was always placed at the
* very end.
*/
size_t i = 0, last_char_width[4] = {}, k = 0;
assert(len > 0); /* at least a terminating NUL */
for (;;) {
char four[4];
int w;
if (*s == 0) /* terminating NUL detected? then we are done! */
goto done;
w = cescape_char(*s, four);
if (i + w + 1 > len) /* This character doesn't fit into the buffer anymore? In that case let's
* ellipsize at the previous location */
break;
/* OK, there was space, let's add this escaped character to the buffer */
memcpy(buf + i, four, w);
i += w;
/* And remember its width in the ring buffer */
last_char_width[k] = w;
k = (k + 1) % 4;
s++;
}
/* Ellipsation is necessary. This means we might need to truncate the string again to make space for 4
* characters ideally, but the buffer is shorter than that in the first place take what we can get */
for (size_t j = 0; j < ELEMENTSOF(last_char_width); j++) {
if (i + 4 <= len) /* nice, we reached our space goal */
break;
k = k == 0 ? 3 : k - 1;
if (last_char_width[k] == 0) /* bummer, we reached the beginning of the strings */
break;
assert(i >= last_char_width[k]);
i -= last_char_width[k];
}
if (i + 4 <= len) /* yay, enough space */
i += write_ellipsis(buf + i, false);
else if (i + 3 <= len) { /* only space for ".." */
buf[i++] = '.';
buf[i++] = '.';
} else if (i + 2 <= len) /* only space for a single "." */
buf[i++] = '.';
else
assert(i + 1 <= len);
done:
buf[i] = '\0';
return buf;
}
char* strshorten(char *s, size_t l) {
assert(s);
if (strnlen(s, l+1) > l)
s[l] = 0;
return s;
}
int strgrowpad0(char **s, size_t l) {
size_t sz;
assert(s);
if (*s) {
sz = strlen(*s) + 1;
if (sz >= l) /* never shrink */
return 0;
} else
sz = 0;
char *q = realloc(*s, l);
if (!q)
return -ENOMEM;
*s = q;
memzero(*s + sz, l - sz);
return 0;
}
char *strreplace(const char *text, const char *old_string, const char *new_string) {
size_t l, old_len, new_len;
char *t, *ret = NULL;
const char *f;
assert(old_string);
assert(new_string);
if (!text)
return NULL;
old_len = strlen(old_string);
new_len = strlen(new_string);
l = strlen(text);
if (!GREEDY_REALLOC(ret, l+1))
return NULL;
f = text;
t = ret;
while (*f) {
size_t d, nl;
if (!startswith(f, old_string)) {
*(t++) = *(f++);
continue;
}
d = t - ret;
nl = l - old_len + new_len;
if (!GREEDY_REALLOC(ret, nl + 1))
return mfree(ret);
l = nl;
t = ret + d;
t = stpcpy(t, new_string);
f += old_len;
}
*t = 0;
return ret;
}
static void advance_offsets(
ssize_t diff,
size_t offsets[2], /* note: we can't use [static 2] here, since this may be NULL */
size_t shift[static 2],
size_t size) {
if (!offsets)
return;
assert(shift);
if ((size_t) diff < offsets[0])
shift[0] += size;
if ((size_t) diff < offsets[1])
shift[1] += size;
}
char *strip_tab_ansi(char **ibuf, size_t *_isz, size_t highlight[2]) {
const char *begin = NULL;
enum {
STATE_OTHER,
STATE_ESCAPE,
STATE_CSI,
STATE_CSO,
} state = STATE_OTHER;
_cleanup_(memstream_done) MemStream m = {};
size_t isz, shift[2] = {}, n_carriage_returns = 0;
FILE *f;
assert(ibuf);
assert(*ibuf);
/* This does three things:
*
* 1. Replaces TABs by 8 spaces
* 2. Strips ANSI color sequences (a subset of CSI), i.e. ESC '[' … 'm' sequences
* 3. Strips ANSI operating system sequences (CSO), i.e. ESC ']' … BEL sequences
* 4. Strip trailing \r characters (since they would "move the cursor", but have no
* other effect).
*
* Everything else will be left as it is. In particular other ANSI sequences are left as they are, as
* are any other special characters. Truncated ANSI sequences are left-as is too. This call is
* supposed to suppress the most basic formatting noise, but nothing else.
*
* Why care for CSO sequences? Well, to undo what terminal_urlify() and friends generate. */
isz = _isz ? *_isz : strlen(*ibuf);
/* Note we turn off internal locking on f for performance reasons. It's safe to do so since we
* created f here and it doesn't leave our scope. */
f = memstream_init(&m);
if (!f)
return NULL;
for (const char *i = *ibuf; i < *ibuf + isz + 1; i++) {
switch (state) {
case STATE_OTHER:
if (i >= *ibuf + isz) /* EOT */
break;
if (*i == '\r') {
n_carriage_returns++;
break;
} else if (*i == '\n')
/* Ignore carriage returns before new line */
n_carriage_returns = 0;
for (; n_carriage_returns > 0; n_carriage_returns--)
fputc('\r', f);
if (*i == '\x1B')
state = STATE_ESCAPE;
else if (*i == '\t') {
fputs(" ", f);
advance_offsets(i - *ibuf, highlight, shift, 7);
} else
fputc(*i, f);
break;
case STATE_ESCAPE:
assert(n_carriage_returns == 0);
if (i >= *ibuf + isz) { /* EOT */
fputc('\x1B', f);
advance_offsets(i - *ibuf, highlight, shift, 1);
break;
} else if (*i == '[') { /* ANSI CSI */
state = STATE_CSI;
begin = i + 1;
} else if (*i == ']') { /* ANSI CSO */
state = STATE_CSO;
begin = i + 1;
} else {
fputc('\x1B', f);
fputc(*i, f);
advance_offsets(i - *ibuf, highlight, shift, 1);
state = STATE_OTHER;
}
break;
case STATE_CSI:
assert(n_carriage_returns == 0);
if (i >= *ibuf + isz || /* EOT … */
!strchr("01234567890;m", *i)) { /* … or invalid chars in sequence */
fputc('\x1B', f);
fputc('[', f);
advance_offsets(i - *ibuf, highlight, shift, 2);
state = STATE_OTHER;
i = begin-1;
} else if (*i == 'm')
state = STATE_OTHER;
break;
case STATE_CSO:
assert(n_carriage_returns == 0);
if (i >= *ibuf + isz || /* EOT … */
(*i != '\a' && (uint8_t) *i < 32U) || (uint8_t) *i > 126U) { /* … or invalid chars in sequence */
fputc('\x1B', f);
fputc(']', f);
advance_offsets(i - *ibuf, highlight, shift, 2);
state = STATE_OTHER;
i = begin-1;
} else if (*i == '\a')
state = STATE_OTHER;
break;
}
}
char *obuf;
if (memstream_finalize(&m, &obuf, _isz) < 0)
return NULL;
free_and_replace(*ibuf, obuf);
if (highlight) {
highlight[0] += shift[0];
highlight[1] += shift[1];
}
return *ibuf;
}
char *strextend_with_separator_internal(char **x, const char *separator, ...) {
size_t f, l, l_separator;
bool need_separator;
char *nr, *p;
va_list ap;
assert(x);
l = f = strlen_ptr(*x);
need_separator = !isempty(*x);
l_separator = strlen_ptr(separator);
va_start(ap, separator);
for (;;) {
const char *t;
size_t n;
t = va_arg(ap, const char *);
if (!t)
break;
n = strlen(t);
if (need_separator)
n += l_separator;
if (n >= SIZE_MAX - l) {
va_end(ap);
return NULL;
}
l += n;
need_separator = true;
}
va_end(ap);
need_separator = !isempty(*x);
nr = realloc(*x, GREEDY_ALLOC_ROUND_UP(l+1));
if (!nr)
return NULL;
*x = nr;
p = nr + f;
va_start(ap, separator);
for (;;) {
const char *t;
t = va_arg(ap, const char *);
if (!t)
break;
if (need_separator && separator)
p = stpcpy(p, separator);
p = stpcpy(p, t);
need_separator = true;
}
va_end(ap);
assert(p == nr + l);
*p = 0;
return p;
}
int strextendf_with_separator(char **x, const char *separator, const char *format, ...) {
size_t m, a, l_separator;
va_list ap;
int l;
/* Appends a formatted string to the specified string. Don't use this in inner loops, since then
* we'll spend a tonload of time in determining the length of the string passed in, over and over
* again. */
assert(x);
assert(format);
l_separator = isempty(*x) ? 0 : strlen_ptr(separator);
/* Let's try to use the allocated buffer, if there's room at the end still. Otherwise let's extend by 64 chars. */
if (*x) {
m = strlen(*x);
a = MALLOC_SIZEOF_SAFE(*x);
assert(a >= m + 1);
} else
m = a = 0;
if (a - m < 17 + l_separator) { /* if there's less than 16 chars space, then enlarge the buffer first */
char *n;
if (_unlikely_(l_separator > SIZE_MAX - 64)) /* overflow check #1 */
return -ENOMEM;
if (_unlikely_(m > SIZE_MAX - 64 - l_separator)) /* overflow check #2 */
return -ENOMEM;
n = realloc(*x, m + 64 + l_separator);
if (!n)
return -ENOMEM;
*x = n;
a = MALLOC_SIZEOF_SAFE(*x);
}
/* Now, let's try to format the string into it */
memcpy_safe(*x + m, separator, l_separator);
va_start(ap, format);
l = vsnprintf(*x + m + l_separator, a - m - l_separator, format, ap);
va_end(ap);
assert(l >= 0);
if ((size_t) l < a - m - l_separator) {
char *n;
/* Nice! This worked. We are done. But first, let's return the extra space we don't
* need. This should be a cheap operation, since we only lower the allocation size here,
* never increase. */
n = realloc(*x, m + (size_t) l + l_separator + 1);
if (n)
*x = n;
} else {
char *n;
/* Wasn't enough. Then let's allocate exactly what we need. */
if (_unlikely_((size_t) l > SIZE_MAX - (l_separator + 1))) /* overflow check #1 */
goto oom;
if (_unlikely_(m > SIZE_MAX - ((size_t) l + l_separator + 1))) /* overflow check #2 */
goto oom;
a = m + (size_t) l + l_separator + 1;
n = realloc(*x, a);
if (!n)
goto oom;
*x = n;
va_start(ap, format);
l = vsnprintf(*x + m + l_separator, a - m - l_separator, format, ap);
va_end(ap);
assert((size_t) l < a - m - l_separator);
}
return 0;
oom:
/* truncate the bytes added after the first vsnprintf() attempt again */
(*x)[m] = 0;
return -ENOMEM;
}
char *strextendn(char **x, const char *s, size_t l) {
assert(x);
assert(s || l == 0);
if (l == SIZE_MAX)
l = strlen_ptr(s);
else if (l > 0)
l = strnlen(s, l); /* ignore trailing noise */
if (l > 0 || !*x) {
size_t q;
char *m;
q = strlen_ptr(*x);
m = realloc(*x, q + l + 1);
if (!m)
return NULL;
memcpy_safe(m + q, s, l);
m[q + l] = 0;
*x = m;
}
return *x;
}
char *strrep(const char *s, unsigned n) {
char *r, *p;
size_t l;
assert(s);
l = strlen(s);
p = r = malloc(l * n + 1);
if (!r)
return NULL;
for (unsigned 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 a 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_and_replace(*p, t);
return 1;
}
int free_and_strndup(char **p, const char *s, size_t l) {
char *t;
assert(p);
assert(s || l == 0);
/* Replaces a string pointer with a strndup()ed new string,
* freeing the old one. */
if (!*p && !s)
return 0;
if (*p && s && strneq(*p, s, l) && (l > strlen(*p) || (*p)[l] == '\0'))
return 0;
if (s) {
t = strndup(s, l);
if (!t)
return -ENOMEM;
} else
t = NULL;
free_and_replace(*p, t);
return 1;
}
bool string_is_safe(const char *p) {
if (!p)
return false;
/* Checks if the specified string contains no quotes or control characters */
for (const char *t = p; *t; t++) {
if (*t > 0 && *t < ' ') /* no control characters */
return false;
if (strchr(QUOTES "\\\x7f", *t))
return false;
}
return true;
}
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_safe(x, strlen(x));
return x;
}
int string_truncate_lines(const char *s, size_t n_lines, char **ret) {
const char *p = s, *e = s;
bool truncation_applied = false;
char *copy;
size_t n = 0;
assert(s);
/* Truncate after the specified number of lines. Returns > 0 if a truncation was applied or == 0 if
* there were fewer lines in the string anyway. Trailing newlines on input are ignored, and not
* generated either. */
for (;;) {
size_t k;
k = strcspn(p, "\n");
if (p[k] == 0) {
if (k == 0) /* final empty line */
break;
if (n >= n_lines) /* above threshold */
break;
e = p + k; /* last line to include */
break;
}
assert(p[k] == '\n');
if (n >= n_lines)
break;
if (k > 0)
e = p + k;
p += k + 1;
n++;
}
/* e points after the last character we want to keep */
if (isempty(e))
copy = strdup(s);
else {
if (!in_charset(e, "\n")) /* We only consider things truncated if we remove something that
* isn't a new-line or a series of them */
truncation_applied = true;
copy = strndup(s, e - s);
}
if (!copy)
return -ENOMEM;
*ret = copy;
return truncation_applied;
}
int string_extract_line(const char *s, size_t i, char **ret) {
const char *p = s;
size_t c = 0;
/* Extract the i'nth line from the specified string. Returns > 0 if there are more lines after that,
* and == 0 if we are looking at the last line or already beyond the last line. As special
* optimization, if the first line is requested and the string only consists of one line we return
* NULL, indicating the input string should be used as is, and avoid a memory allocation for a very
* common case. */
for (;;) {
const char *q;
q = strchr(p, '\n');
if (i == c) {
/* The line we are looking for! */
if (q) {
char *m;
m = strndup(p, q - p);
if (!m)
return -ENOMEM;
*ret = m;
return !isempty(q + 1); /* more coming? */
} else {
if (p == s)
*ret = NULL; /* Just use the input string */
else {
char *m;
m = strdup(p);
if (!m)
return -ENOMEM;
*ret = m;
}
return 0; /* The end */
}
}
if (!q) {
char *m;
/* No more lines, return empty line */
m = strdup("");
if (!m)
return -ENOMEM;
*ret = m;
return 0; /* The end */
}
p = q + 1;
c++;
}
}
int string_contains_word_strv(const char *string, const char *separators, char **words, const char **ret_word) {
/* In the default mode with no separators specified, we split on whitespace and
* don't coalesce separators. */
const ExtractFlags flags = separators ? EXTRACT_DONT_COALESCE_SEPARATORS : 0;
const char *found = NULL;
for (const char *p = string;;) {
_cleanup_free_ char *w = NULL;
int r;
r = extract_first_word(&p, &w, separators, flags);
if (r < 0)
return r;
if (r == 0)
break;
found = strv_find(words, w);
if (found)
break;
}
if (ret_word)
*ret_word = found;
return !!found;
}
bool streq_skip_trailing_chars(const char *s1, const char *s2, const char *ok) {
if (!s1 && !s2)
return true;
if (!s1 || !s2)
return false;
if (!ok)
ok = WHITESPACE;
for (; *s1 && *s2; s1++, s2++)
if (*s1 != *s2)
break;
return in_charset(s1, ok) && in_charset(s2, ok);
}
char *string_replace_char(char *str, char old_char, char new_char) {
assert(str);
assert(old_char != '\0');
assert(new_char != '\0');
assert(old_char != new_char);
for (char *p = strchr(str, old_char); p; p = strchr(p + 1, old_char))
*p = new_char;
return str;
}
int make_cstring(const char *s, size_t n, MakeCStringMode mode, char **ret) {
char *b;
assert(s || n == 0);
assert(mode >= 0);
assert(mode < _MAKE_CSTRING_MODE_MAX);
/* Converts a sized character buffer into a NUL-terminated NUL string, refusing if there are embedded
* NUL bytes. Whether to expect a trailing NUL byte can be specified via 'mode' */
if (n == 0) {
if (mode == MAKE_CSTRING_REQUIRE_TRAILING_NUL)
return -EINVAL;
if (!ret)
return 0;
b = new0(char, 1);
} else {
const char *nul;
nul = memchr(s, 0, n);
if (nul) {
if (nul < s + n - 1 || /* embedded NUL? */
mode == MAKE_CSTRING_REFUSE_TRAILING_NUL)
return -EINVAL;
n--;
} else if (mode == MAKE_CSTRING_REQUIRE_TRAILING_NUL)
return -EINVAL;
if (!ret)
return 0;
b = memdup_suffix0(s, n);
}
if (!b)
return -ENOMEM;
*ret = b;
return 0;
}
size_t strspn_from_end(const char *str, const char *accept) {
size_t n = 0;
if (isempty(str))
return 0;
if (isempty(accept))
return 0;
for (const char *p = str + strlen(str); p > str && strchr(accept, p[-1]); p--)
n++;
return n;
}
char *strdupspn(const char *a, const char *accept) {
if (isempty(a) || isempty(accept))
return strdup("");
return strndup(a, strspn(a, accept));
}
char *strdupcspn(const char *a, const char *reject) {
if (isempty(a))
return strdup("");
if (isempty(reject))
return strdup(a);
return strndup(a, strcspn(a, reject));
}
char *find_line_startswith(const char *haystack, const char *needle) {
char *p;
assert(haystack);
assert(needle);
/* Finds the first line in 'haystack' that starts with the specified string. Returns a pointer to the
* first character after it */
p = strstr(haystack, needle);
if (!p)
return NULL;
if (p > haystack)
while (p[-1] != '\n') {
p = strstr(p + 1, needle);
if (!p)
return NULL;
}
return p + strlen(needle);
}
bool version_is_valid(const char *s) {
if (isempty(s))
return false;
if (!filename_part_is_valid(s))
return false;
/* This is a superset of the characters used by semver. We additionally allow "," and "_". */
if (!in_charset(s, ALPHANUMERICAL ".,_-+"))
return false;
return true;
}
bool version_is_valid_versionspec(const char *s) {
if (!filename_part_is_valid(s))
return false;
if (!in_charset(s, ALPHANUMERICAL "-.~^"))
return false;
return true;
}
ssize_t strlevenshtein(const char *x, const char *y) {
_cleanup_free_ size_t *t0 = NULL, *t1 = NULL, *t2 = NULL;
size_t xl, yl;
/* This is inspired from the Linux kernel's Levenshtein implementation */
if (streq_ptr(x, y))
return 0;
xl = strlen_ptr(x);
if (xl > SSIZE_MAX)
return -E2BIG;
yl = strlen_ptr(y);
if (yl > SSIZE_MAX)
return -E2BIG;
if (isempty(x))
return yl;
if (isempty(y))
return xl;
t0 = new0(size_t, yl + 1);
if (!t0)
return -ENOMEM;
t1 = new0(size_t, yl + 1);
if (!t1)
return -ENOMEM;
t2 = new0(size_t, yl + 1);
if (!t2)
return -ENOMEM;
for (size_t i = 0; i <= yl; i++)
t1[i] = i;
for (size_t i = 0; i < xl; i++) {
t2[0] = i + 1;
for (size_t j = 0; j < yl; j++) {
/* Substitution */
t2[j+1] = t1[j] + (x[i] != y[j]);
/* Swap */
if (i > 0 && j > 0 && x[i-1] == y[j] && x[i] == y[j-1] && t2[j+1] > t0[j-1] + 1)
t2[j+1] = t0[j-1] + 1;
/* Deletion */
if (t2[j+1] > t1[j+1] + 1)
t2[j+1] = t1[j+1] + 1;
/* Insertion */
if (t2[j+1] > t2[j] + 1)
t2[j+1] = t2[j] + 1;
}
size_t *dummy = t0;
t0 = t1;
t1 = t2;
t2 = dummy;
}
return t1[yl];
}
char *strrstr(const char *haystack, const char *needle) {
/* Like strstr() but returns the last rather than the first occurrence of "needle" in "haystack". */
if (!haystack || !needle)
return NULL;
/* Special case: for the empty string we return the very last possible occurrence, i.e. *after* the
* last char, not before. */
if (*needle == 0)
return strchr(haystack, 0);
for (const char *p = strstr(haystack, needle), *q; p; p = q) {
q = strstr(p + 1, needle);
if (!q)
return (char *) p;
}
return NULL;
}
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