src/str.h

   1 /* dynamic string handling */
   2 /* Copyright (c) Olly Betts 1999, 2001, 2012, 2014, 2024
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License as published by
   6  * the Free Software Foundation; either version 2 of the License, or
   7  * (at your option) any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, write to the Free Software
  16  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  17  */
  18
  19 #ifndef SURVEX_INCLUDED_STR_H
  20 #define SURVEX_INCLUDED_STR_H
  21
  22 #include "osalloc.h"
  23 #include <string.h>
  24
  25 typedef struct {
  26     char *s;
  27     int len;
  28     int capacity; /* One less than the allocated size! */
  29 } string;
  30
  31 // string foo = S_INIT;
  32 #define S_INIT { NULL, 0, 0 }
  33
  34 void s_expand_(string *pstr, int addition);
  35
  36 /* Append a block of text with given length. */
  37 void s_appendlen(string *pstr, const char *s, int s_len);
  38
  39 void s_appendn(string *pstr, int n, char c);
  40
  41 /* Append another string. */
  42 static inline void s_appends(string *pstr, const string *s) {
  43     s_appendlen(pstr, s->s, s->len);
  44 }
  45
  46 /* Append a C string. */
  47 static inline void s_append(string *pstr, const char *s) {
  48     s_appendlen(pstr, s, strlen(s));
  49 }
  50
  51 /* Append a character */
  52 static inline void s_appendch(string *pstr, char c) {
  53     if (pstr->capacity == pstr->len) s_expand_(pstr, 1);
  54     pstr->s[pstr->len++] = c;
  55 }
  56
  57 /* Truncate string to zero length (and ensure it isn't NULL). */
  58 static inline void s_clear(string *pstr) {
  59     if (pstr->s == NULL) s_expand_(pstr, 0);
  60     pstr->len = 0;
  61 }
  62
  63 /* Truncate string */
  64 static inline void s_truncate(string *pstr, int new_len) {
  65     if (new_len < pstr->len) {
  66         pstr->len = new_len;
  67         pstr->s[new_len] = '\0';
  68     }
  69 }
  70
  71 /* Release allocated memory. */
  72 static inline void s_free(string *pstr) {
  73     osfree(pstr->s);
  74     pstr->s = NULL;
  75     pstr->len = 0;
  76     pstr->capacity = 0;
  77 }
  78
  79 /* Steal the C string. */
  80 static inline char *s_steal(string *pstr) {
  81     char *s = pstr->s;
  82     s[pstr->len] = '\0';
  83     pstr->s = NULL;
  84     pstr->len = 0;
  85     pstr->capacity = 0;
  86     return s;
  87 }
  88
  89 /* Donate a malloc-ed C string. */
  90 static inline void s_donate(string *pstr, char *s) {
  91     osfree(pstr->s);
  92     pstr->s = s;
  93     pstr->capacity = pstr->len = strlen(s);
  94 }
  95
  96 static inline int s_len(const string *pstr) { return pstr->len; }
  97
  98 static inline bool s_empty(const string *pstr) { return pstr->len == 0; }
  99
 100 static inline const char *s_str(string *pstr) {
 101     char *s = pstr->s;
 102     if (s) s[pstr->len] = '\0';
 103     return s;
 104 }
 105
 106 static inline bool s_eqlen(const string *pstr, const char *s, int s_len) {
 107     return pstr->len == s_len && memcmp(pstr->s, s, s_len) == 0;
 108 }
 109
 110 static inline bool s_eq(const string *pstr, const char *s) {
 111     return strncmp(pstr->s, s, pstr->len) == 0 && s[pstr->len] == '\0';
 112 }
 113
 114 static inline char s_back(const string *pstr) {
 115     return pstr->s[pstr->len - 1];
 116 }
 117
 118 #define S_EQ(PSTR, LITERAL) s_eqlen((PSTR), LITERAL, sizeof(LITERAL "") - 1)
 119
 120 #endif // SURVEX_INCLUDED_STR_H