src/basic/string-util.h

   1 /* SPDX-License-Identifier: LGPL-2.1+ */
   2 #pragma once
   3
   4 #include <alloca.h>
   5 #include <stdbool.h>
   6 #include <stddef.h>
   7 #include <string.h>
   8
   9 #include "alloc-util.h"
  10 #include "macro.h"
  11
  12 /* What is interpreted as whitespace? */
  13 #define WHITESPACE        " \t\n\r"
  14 #define NEWLINE           "\n\r"
  15 #define QUOTES            "\"\'"
  16 #define COMMENTS          "#;"
  17 #define GLOB_CHARS        "*?["
  18 #define DIGITS            "0123456789"
  19 #define LOWERCASE_LETTERS "abcdefghijklmnopqrstuvwxyz"
  20 #define UPPERCASE_LETTERS "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
  21 #define LETTERS           LOWERCASE_LETTERS UPPERCASE_LETTERS
  22 #define ALPHANUMERICAL    LETTERS DIGITS
  23 #define HEXDIGITS         DIGITS "abcdefABCDEF"
  24
  25 #define streq(a,b) (strcmp((a),(b)) == 0)
  26 #define strneq(a, b, n) (strncmp((a), (b), (n)) == 0)
  27 #define strcaseeq(a,b) (strcasecmp((a),(b)) == 0)
  28 #define strncaseeq(a, b, n) (strncasecmp((a), (b), (n)) == 0)
  29
  30 int strcmp_ptr(const char *a, const char *b) _pure_;
  31
  32 static inline bool streq_ptr(const char *a, const char *b) {
  33         return strcmp_ptr(a, b) == 0;
  34 }
  35
  36 static inline const char* strempty(const char *s) {
  37         return s ?: "";
  38 }
  39
  40 static inline const char* strnull(const char *s) {
  41         return s ?: "(null)";
  42 }
  43
  44 static inline const char *strna(const char *s) {
  45         return s ?: "n/a";
  46 }
  47
  48 static inline bool isempty(const char *p) {
  49         return !p || !p[0];
  50 }
  51
  52 static inline const char *empty_to_null(const char *p) {
  53         return isempty(p) ? NULL : p;
  54 }
  55
  56 static inline const char *empty_to_dash(const char *str) {
  57         return isempty(str) ? "-" : str;
  58 }
  59
  60 static inline char *startswith(const char *s, const char *prefix) {
  61         size_t l;
  62
  63         l = strlen(prefix);
  64         if (strncmp(s, prefix, l) == 0)
  65                 return (char*) s + l;
  66
  67         return NULL;
  68 }
  69
  70 static inline char *startswith_no_case(const char *s, const char *prefix) {
  71         size_t l;
  72
  73         l = strlen(prefix);
  74         if (strncasecmp(s, prefix, l) == 0)
  75                 return (char*) s + l;
  76
  77         return NULL;
  78 }
  79
  80 char *endswith(const char *s, const char *postfix) _pure_;
  81 char *endswith_no_case(const char *s, const char *postfix) _pure_;
  82
  83 char *first_word(const char *s, const char *word) _pure_;
  84
  85 typedef enum SplitFlags {
  86         SPLIT_QUOTES                     = 0x01 << 0,
  87         SPLIT_RELAX                      = 0x01 << 1,
  88 } SplitFlags;
  89
  90 const char* split(const char **state, size_t *l, const char *separator, SplitFlags flags);
  91
  92 #define FOREACH_WORD(word, length, s, state)                            \
  93         _FOREACH_WORD(word, length, s, WHITESPACE, 0, state)
  94
  95 #define FOREACH_WORD_SEPARATOR(word, length, s, separator, state)       \
  96         _FOREACH_WORD(word, length, s, separator, 0, state)
  97
  98 #define _FOREACH_WORD(word, length, s, separator, flags, state)         \
  99         for ((state) = (s), (word) = split(&(state), &(length), (separator), (flags)); (word); (word) = split(&(state), &(length), (separator), (flags)))
 100
 101 char *strappend(const char *s, const char *suffix);
 102 char *strnappend(const char *s, const char *suffix, size_t length);
 103
 104 char *strjoin_real(const char *x, ...) _sentinel_;
 105 #define strjoin(a, ...) strjoin_real((a), __VA_ARGS__, NULL)
 106
 107 #define strjoina(a, ...)                                                \
 108         ({                                                              \
 109                 const char *_appendees_[] = { a, __VA_ARGS__ };         \
 110                 char *_d_, *_p_;                                        \
 111                 size_t _len_ = 0;                                          \
 112                 size_t _i_;                                           \
 113                 for (_i_ = 0; _i_ < ELEMENTSOF(_appendees_) && _appendees_[_i_]; _i_++) \
 114                         _len_ += strlen(_appendees_[_i_]);              \
 115                 _p_ = _d_ = newa(char, _len_ + 1);                      \
 116                 for (_i_ = 0; _i_ < ELEMENTSOF(_appendees_) && _appendees_[_i_]; _i_++) \
 117                         _p_ = stpcpy(_p_, _appendees_[_i_]);            \
 118                 *_p_ = 0;                                               \
 119                 _d_;                                                    \
 120         })
 121
 122 char *strstrip(char *s);
 123 char *delete_chars(char *s, const char *bad);
 124 char *delete_trailing_chars(char *s, const char *bad);
 125 char *truncate_nl(char *s);
 126
 127 static inline char *skip_leading_chars(const char *s, const char *bad) {
 128
 129         if (!s)
 130                 return NULL;
 131
 132         if (!bad)
 133                 bad = WHITESPACE;
 134
 135         return (char*) s + strspn(s, bad);
 136 }
 137
 138 char ascii_tolower(char x);
 139 char *ascii_strlower(char *s);
 140 char *ascii_strlower_n(char *s, size_t n);
 141
 142 char ascii_toupper(char x);
 143 char *ascii_strupper(char *s);
 144
 145 int ascii_strcasecmp_n(const char *a, const char *b, size_t n);
 146 int ascii_strcasecmp_nn(const char *a, size_t n, const char *b, size_t m);
 147
 148 bool chars_intersect(const char *a, const char *b) _pure_;
 149
 150 static inline bool _pure_ in_charset(const char *s, const char* charset) {
 151         assert(s);
 152         assert(charset);
 153         return s[strspn(s, charset)] == '\0';
 154 }
 155
 156 bool string_has_cc(const char *p, const char *ok) _pure_;
 157
 158 char *ellipsize_mem(const char *s, size_t old_length_bytes, size_t new_length_columns, unsigned percent);
 159 static inline char *ellipsize(const char *s, size_t length, unsigned percent) {
 160         return ellipsize_mem(s, strlen(s), length, percent);
 161 }
 162
 163 char *cellescape(char *buf, size_t len, const char *s);
 164
 165 /* This limit is arbitrary, enough to give some idea what the string contains */
 166 #define CELLESCAPE_DEFAULT_LENGTH 64
 167
 168 bool nulstr_contains(const char *nulstr, const char *needle);
 169
 170 char* strshorten(char *s, size_t l);
 171
 172 char *strreplace(const char *text, const char *old_string, const char *new_string);
 173
 174 char *strip_tab_ansi(char **ibuf, size_t *_isz, size_t highlight[2]);
 175
 176 char *strextend_with_separator(char **x, const char *separator, ...) _sentinel_;
 177
 178 #define strextend(x, ...) strextend_with_separator(x, NULL, __VA_ARGS__)
 179
 180 char *strrep(const char *s, unsigned n);
 181
 182 int split_pair(const char *s, const char *sep, char **l, char **r);
 183
 184 int free_and_strdup(char **p, const char *s);
 185 int free_and_strndup(char **p, const char *s, size_t l);
 186
 187 /* Normal memmem() requires haystack to be nonnull, which is annoying for zero-length buffers */
 188 static inline void *memmem_safe(const void *haystack, size_t haystacklen, const void *needle, size_t needlelen) {
 189
 190         if (needlelen <= 0)
 191                 return (void*) haystack;
 192
 193         if (haystacklen < needlelen)
 194                 return NULL;
 195
 196         assert(haystack);
 197         assert(needle);
 198
 199         return memmem(haystack, haystacklen, needle, needlelen);
 200 }
 201
 202 #if HAVE_EXPLICIT_BZERO
 203 static inline void* explicit_bzero_safe(void *p, size_t l) {
 204         if (l > 0)
 205                 explicit_bzero(p, l);
 206
 207         return p;
 208 }
 209 #else
 210 void *explicit_bzero_safe(void *p, size_t l);
 211 #endif
 212
 213 char *string_erase(char *x);
 214
 215 char *string_free_erase(char *s);
 216 DEFINE_TRIVIAL_CLEANUP_FUNC(char *, string_free_erase);
 217 #define _cleanup_string_free_erase_ _cleanup_(string_free_erasep)
 218
 219 bool string_is_safe(const char *p) _pure_;
 220
 221 static inline size_t strlen_ptr(const char *s) {
 222         if (!s)
 223                 return 0;
 224
 225         return strlen(s);
 226 }
 227
 228 /* Like startswith(), but operates on arbitrary memory blocks */
 229 static inline void *memory_startswith(const void *p, size_t sz, const char *token) {
 230         size_t n;
 231
 232         assert(token);
 233
 234         n = strlen(token);
 235         if (sz < n)
 236                 return NULL;
 237
 238         assert(p);
 239
 240         if (memcmp(p, token, n) != 0)
 241                 return NULL;
 242
 243         return (uint8_t*) p + n;
 244 }
 245
 246 /* Like startswith_no_case(), but operates on arbitrary memory blocks.
 247  * It works only for ASCII strings.
 248  */
 249 static inline void *memory_startswith_no_case(const void *p, size_t sz, const char *token) {
 250         size_t n, i;
 251
 252         assert(token);
 253
 254         n = strlen(token);
 255         if (sz < n)
 256                 return NULL;
 257
 258         assert(p);
 259
 260         for (i = 0; i < n; i++) {
 261                 if (ascii_tolower(((char *)p)[i]) != ascii_tolower(token[i]))
 262                         return NULL;
 263         }
 264
 265         return (uint8_t*) p + n;
 266 }