Adding upstream version 247.3.upstream/247.3upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1136 insertions, 0 deletions

diff --git a/src/basic/string-util.c b/src/basic/string-util.c
new file mode 100644
index 0000000..7ab460f
--- /dev/null
+++ b/src/basic/string-util.c
@@ -0,0 +1,1136 @@
+/* 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"
+
+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);
+        return CMP(a, b); /* Direct comparison of pointers, one of which is NULL */
+}
+
+int strcasecmp_ptr(const char *a, const char *b) {
+        /* Like strcasecmp(), but tries to make sense of NULL pointers */
+
+        if (a && b)
+                return strcasecmp(a, b);
+        return CMP(a, b); /* Direct comparison of pointers, one of which is NULL */
+}
+
+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;
+}
+
+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 *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 *p, *c = s;
+
+        /* Drops all specified bad characters, at the end of the string */
+
+        if (!s)
+                return NULL;
+
+        if (!bad)
+                bad = WHITESPACE;
+
+        for (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) {
+        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;
+
+        return CMP(n, m);
+}
+
+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 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_t) -1);
+
+        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_t) -1)
+                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, j;
+
+        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 (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;
+}
+
+char *strreplace(const char *text, const char *old_string, const char *new_string) {
+        size_t l, old_len, new_len, allocated = 0;
+        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, allocated, 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, allocated, 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(char **x, const char *separator, ...) {
+        bool need_separator;
+        size_t f, l, l_separator;
+        char *r, *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_t) -1) - l) {
+                        va_end(ap);
+                        return NULL;
+                }
+
+                l += n;
+                need_separator = true;
+        }
+        va_end(ap);
+
+        need_separator = !isempty(*x);
+
+        r = realloc(*x, l+1);
+        if (!r)
+                return NULL;
+
+        p = r + 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 == r + l);
+
+        *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 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) {
+        const char *t;
+
+        if (!p)
+                return false;
+
+        /* Checks if the specified string contains no quotes or control characters */
+
+        for (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;
+}