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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 15:35:18 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 15:35:18 +0000 |
commit | b750101eb236130cf056c675997decbac904cc49 (patch) | |
tree | a5df1a06754bdd014cb975c051c83b01c9a97532 /src/basic/string-util.c | |
parent | Initial commit. (diff) | |
download | systemd-upstream.tar.xz systemd-upstream.zip |
Adding upstream version 252.22.upstream/252.22upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r-- | src/basic/string-util.c | 1204 |
1 files changed, 1204 insertions, 0 deletions
diff --git a/src/basic/string-util.c b/src/basic/string-util.c new file mode 100644 index 0000000..17d35fe --- /dev/null +++ b/src/basic/string-util.c @@ -0,0 +1,1204 @@ +/* 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 "fileio.h" +#include "gunicode.h" +#include "locale-util.h" +#include "macro.h" +#include "memory-util.h" +#include "string-util.h" +#include "strv.h" +#include "terminal-util.h" +#include "utf8.h" +#include "util.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(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) { + 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 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; + char *e; + 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(""); + + /* If no multibyte characters use ascii_ellipsize_mem for speed */ + if (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; i = utf8_next_char(i)) { + char32_t c; + int w; + + r = utf8_encoded_to_unichar(i, &c); + if (r < 0) + return NULL; + + w = unichar_iswide(c) ? 2 : 1; + if (k + w <= x) + k += w; + else + break; + } + + for (j = s + old_length; j > i; ) { + char32_t c; + int w; + const char *jj; + + jj = utf8_prev_char(j); + r = utf8_encoded_to_unichar(jj, &c); + if (r < 0) + return NULL; + + w = unichar_iswide(c) ? 2 : 1; + if (k + w <= new_length) { + k += w; + j = jj; + } else + break; + } + assert(i <= j); + + /* we don't actually need to ellipsize */ + if (i == j) + return memdup_suffix0(s, old_length); + + /* make space for ellipsis, if possible */ + 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; + 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); + write_ellipsis(e + len, true); + memcpy(e + len + 3, j, len2); + *(e + len + 3 + 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) { + assert(s); + + char *q = realloc(*s, l); + if (!q) + return -ENOMEM; + *s = q; + + size_t sz = strlen(*s); + 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; + char *obuf = NULL; + size_t osz = 0, 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 = open_memstream_unlocked(&obuf, &osz); + 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; + } + } + + if (fflush_and_check(f) < 0) { + fclose(f); + return mfree(obuf); + } + fclose(f); + + free_and_replace(*ibuf, obuf); + + if (_isz) + *_isz = osz; + + 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 *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(*p); + *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; +} + +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; +} |