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apr_strings.h
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8  * http://www.apache.org/licenses/LICENSE-2.0
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16 
17 /* Portions of this file are covered by */
18 /* -*- mode: c; c-file-style: "k&r" -*-
19 
20  strnatcmp.c -- Perform 'natural order' comparisons of strings in C.
21  Copyright (C) 2000 by Martin Pool <mbp@humbug.org.au>
22 
23  This software is provided 'as-is', without any express or implied
24  warranty. In no event will the authors be held liable for any damages
25  arising from the use of this software.
26 
27  Permission is granted to anyone to use this software for any purpose,
28  including commercial applications, and to alter it and redistribute it
29  freely, subject to the following restrictions:
30 
31  1. The origin of this software must not be misrepresented; you must not
32  claim that you wrote the original software. If you use this software
33  in a product, an acknowledgment in the product documentation would be
34  appreciated but is not required.
35  2. Altered source versions must be plainly marked as such, and must not be
36  misrepresented as being the original software.
37  3. This notice may not be removed or altered from any source distribution.
38 */
39 
40 #ifndef APR_STRINGS_H
41 #define APR_STRINGS_H
42 
43 /**
44  * @file apr_strings.h
45  * @brief APR Strings library
46  */
47 
48 #include "apr.h"
49 #include "apr_errno.h"
50 #include "apr_pools.h"
51 #define APR_WANT_IOVEC
52 #include "apr_want.h"
53 
54 #if APR_HAVE_STDARG_H
55 #include <stdarg.h>
56 #endif
57 
58 #ifdef __cplusplus
59 extern "C" {
60 #endif /* __cplusplus */
61 
62 /**
63  * @defgroup apr_strings String routines
64  * @ingroup APR
65  * @{
66  */
67 
68 /**
69  * Do a natural order comparison of two strings.
70  * @param a The first string to compare
71  * @param b The second string to compare
72  * @return Either <0, 0, or >0. If the first string is less than the second
73  * this returns <0, if they are equivalent it returns 0, and if the
74  * first string is greater than second string it retuns >0.
75  */
76 APR_DECLARE(int) apr_strnatcmp(char const *a, char const *b);
77 
78 /**
79  * Do a natural order comparison of two strings ignoring the case of the
80  * strings.
81  * @param a The first string to compare
82  * @param b The second string to compare
83  * @return Either <0, 0, or >0. If the first string is less than the second
84  * this returns <0, if they are equivalent it returns 0, and if the
85  * first string is greater than second string it retuns >0.
86  */
87 APR_DECLARE(int) apr_strnatcasecmp(char const *a, char const *b);
88 
89 /**
90  * duplicate a string into memory allocated out of a pool
91  * @param p The pool to allocate out of
92  * @param s The string to duplicate
93  * @return The new string or NULL if s == NULL
94  */
95 APR_DECLARE(char *) apr_pstrdup(apr_pool_t *p, const char *s);
96 
97 /**
98  * Create a null-terminated string by making a copy of a sequence
99  * of characters and appending a null byte
100  * @param p The pool to allocate out of
101  * @param s The block of characters to duplicate
102  * @param n The number of characters to duplicate
103  * @return The new string or NULL if s == NULL
104  * @remark This is a faster alternative to apr_pstrndup, for use
105  * when you know that the string being duplicated really
106  * has 'n' or more characters. If the string might contain
107  * fewer characters, use apr_pstrndup.
108  */
109 APR_DECLARE(char *) apr_pstrmemdup(apr_pool_t *p, const char *s, apr_size_t n)
110 #if defined(__GNUC__) && (__GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 4))
111  __attribute__((alloc_size(3)))
112 #endif
113  ;
114 
115 /**
116  * Duplicate at most n characters of a string into memory allocated
117  * out of a pool; the new string will be NUL-terminated
118  * @param p The pool to allocate out of
119  * @param s The string to duplicate
120  * @param n The maximum number of characters to duplicate
121  * @return The new string or NULL if s == NULL
122  * @remark The amount of memory allocated from the pool is the length
123  * of the returned string including the NUL terminator
124  */
125 APR_DECLARE(char *) apr_pstrndup(apr_pool_t *p, const char *s, apr_size_t n);
126 
127 /**
128  * Duplicate a block of memory.
129  *
130  * @param p The pool to allocate from
131  * @param m The memory to duplicate
132  * @param n The number of bytes to duplicate
133  * @return The new block of memory or NULL if m == NULL
134  */
135 APR_DECLARE(void *) apr_pmemdup(apr_pool_t *p, const void *m, apr_size_t n)
136 #if defined(__GNUC__) && (__GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 4))
137  __attribute__((alloc_size(3)))
138 #endif
139  ;
140 
141 /**
142  * Concatenate multiple strings, allocating memory out a pool
143  * @param p The pool to allocate out of
144  * @param ... The strings to concatenate. The final string must be NULL
145  * @return The new string
146  */
148 #if defined(__GNUC__) && __GNUC__ >= 4
149  __attribute__((sentinel))
150 #endif
151  ;
152 
153 /**
154  * Concatenate multiple strings specified in a writev-style vector
155  * @param p The pool from which to allocate
156  * @param vec The strings to concatenate
157  * @param nvec The number of strings to concatenate
158  * @param nbytes (output) strlen of new string (pass in NULL to omit)
159  * @return The new string
160  */
161 APR_DECLARE(char *) apr_pstrcatv(apr_pool_t *p, const struct iovec *vec,
162  apr_size_t nvec, apr_size_t *nbytes);
163 
164 /**
165  * printf-style style printing routine. The data is output to a string
166  * allocated from a pool
167  * @param p The pool to allocate out of
168  * @param fmt The format of the string
169  * @param ap The arguments to use while printing the data
170  * @return The new string
171  */
172 APR_DECLARE(char *) apr_pvsprintf(apr_pool_t *p, const char *fmt, va_list ap);
173 
174 /**
175  * printf-style style printing routine. The data is output to a string
176  * allocated from a pool
177  * @param p The pool to allocate out of
178  * @param fmt The format of the string
179  * @param ... The arguments to use while printing the data
180  * @return The new string
181  */
182 APR_DECLARE_NONSTD(char *) apr_psprintf(apr_pool_t *p, const char *fmt, ...)
183  __attribute__((format(printf,2,3)));
184 
185 /**
186  * Copy up to dst_size characters from src to dst; does not copy
187  * past a NUL terminator in src, but always terminates dst with a NUL
188  * regardless.
189  * @param dst The destination string
190  * @param src The source string
191  * @param dst_size The space available in dst; dst always receives
192  * NUL termination, so if src is longer than
193  * dst_size, the actual number of characters copied is
194  * dst_size - 1.
195  * @return Pointer to the NUL terminator of the destination string, dst
196  * @remark
197  * <PRE>
198  * Note the differences between this function and strncpy():
199  * 1) strncpy() doesn't always NUL terminate; apr_cpystrn() does.
200  * 2) strncpy() pads the destination string with NULs, which is often
201  * unnecessary; apr_cpystrn() does not.
202  * 3) strncpy() returns a pointer to the beginning of the dst string;
203  * apr_cpystrn() returns a pointer to the NUL terminator of dst,
204  * to allow a check for truncation.
205  * </PRE>
206  */
207 APR_DECLARE(char *) apr_cpystrn(char *dst, const char *src,
208  apr_size_t dst_size);
209 
210 /**
211  * Remove all whitespace from a string
212  * @param dest The destination string. It is okay to modify the string
213  * in place. Namely dest == src
214  * @param src The string to rid the spaces from.
215  * @return A pointer to the destination string's null terminator.
216  */
217 APR_DECLARE(char *) apr_collapse_spaces(char *dest, const char *src);
218 
219 /**
220  * Convert the arguments to a program from one string to an array of
221  * strings terminated by a NULL pointer
222  * @param arg_str The arguments to convert
223  * @param argv_out Output location. This is a pointer to an array of strings.
224  * @param token_context Pool to use.
225  */
226 APR_DECLARE(apr_status_t) apr_tokenize_to_argv(const char *arg_str,
227  char ***argv_out,
228  apr_pool_t *token_context);
229 
230 /**
231  * Split a string into separate null-terminated tokens. The tokens are
232  * delimited in the string by one or more characters from the sep
233  * argument.
234  * @param str The string to separate; this should be specified on the
235  * first call to apr_strtok() for a given string, and NULL
236  * on subsequent calls.
237  * @param sep The set of delimiters
238  * @param last State saved by apr_strtok() between calls.
239  * @return The next token from the string
240  * @note the 'last' state points to the trailing NUL char of the final
241  * token, otherwise it points to the character following the current
242  * token (all successive or empty occurances of sep are skiped on the
243  * subsequent call to apr_strtok). Therefore it is possible to avoid
244  * a strlen() determination, with the following logic;
245  * toklen = last - retval; if (*last) --toklen;
246  */
247 APR_DECLARE(char *) apr_strtok(char *str, const char *sep, char **last);
248 
249 /**
250  * @defgroup APR_Strings_Snprintf snprintf implementations
251  * @warning
252  * These are snprintf implementations based on apr_vformatter().
253  *
254  * Note that various standards and implementations disagree on the return
255  * value of snprintf, and side-effects due to %n in the formatting string.
256  * apr_snprintf (and apr_vsnprintf) behaves as follows:
257  *
258  * Process the format string until the entire string is exhausted, or
259  * the buffer fills. If the buffer fills then stop processing immediately
260  * (so no further %n arguments are processed), and return the buffer
261  * length. In all cases the buffer is NUL terminated. It will return the
262  * number of characters inserted into the buffer, not including the
263  * terminating NUL. As a special case, if len is 0, apr_snprintf will
264  * return the number of characters that would have been inserted if
265  * the buffer had been infinite (in this case, *buffer can be NULL)
266  *
267  * In no event does apr_snprintf return a negative number.
268  * @{
269  */
270 
271 /**
272  * snprintf routine based on apr_vformatter. This means it understands the
273  * same extensions.
274  * @param buf The buffer to write to
275  * @param len The size of the buffer
276  * @param format The format string
277  * @param ... The arguments to use to fill out the format string.
278  */
279 APR_DECLARE_NONSTD(int) apr_snprintf(char *buf, apr_size_t len,
280  const char *format, ...)
281  __attribute__((format(printf,3,4)));
282 
283 /**
284  * vsnprintf routine based on apr_vformatter. This means it understands the
285  * same extensions.
286  * @param buf The buffer to write to
287  * @param len The size of the buffer
288  * @param format The format string
289  * @param ap The arguments to use to fill out the format string.
290  */
291 APR_DECLARE(int) apr_vsnprintf(char *buf, apr_size_t len, const char *format,
292  va_list ap);
293 /** @} */
294 
295 /**
296  * create a string representation of an int, allocated from a pool
297  * @param p The pool from which to allocate
298  * @param n The number to format
299  * @return The string representation of the number
300  */
301 APR_DECLARE(char *) apr_itoa(apr_pool_t *p, int n);
302 
303 /**
304  * create a string representation of a long, allocated from a pool
305  * @param p The pool from which to allocate
306  * @param n The number to format
307  * @return The string representation of the number
308  */
309 APR_DECLARE(char *) apr_ltoa(apr_pool_t *p, long n);
310 
311 /**
312  * create a string representation of an apr_off_t, allocated from a pool
313  * @param p The pool from which to allocate
314  * @param n The number to format
315  * @return The string representation of the number
316  */
317 APR_DECLARE(char *) apr_off_t_toa(apr_pool_t *p, apr_off_t n);
318 
319 /**
320  * Convert a numeric string into an apr_off_t numeric value.
321  * @param offset The value of the parsed string.
322  * @param buf The string to parse. It may contain optional whitespace,
323  * followed by an optional '+' (positive, default) or '-' (negative)
324  * character, followed by an optional '0x' prefix if base is 0 or 16,
325  * followed by numeric digits appropriate for base.
326  * @param end A pointer to the end of the valid character in buf. If
327  * not NULL, it is set to the first invalid character in buf.
328  * @param base A numeric base in the range between 2 and 36 inclusive,
329  * or 0. If base is zero, buf will be treated as base ten unless its
330  * digits are prefixed with '0x', in which case it will be treated as
331  * base 16.
332  * @bug *end breaks type safety; where *buf is const, *end needs to be
333  * declared as const in APR 2.0
334  */
335 APR_DECLARE(apr_status_t) apr_strtoff(apr_off_t *offset, const char *buf,
336  char **end, int base);
337 
338 /**
339  * parse a numeric string into a 64-bit numeric value
340  * @param buf The string to parse. It may contain optional whitespace,
341  * followed by an optional '+' (positive, default) or '-' (negative)
342  * character, followed by an optional '0x' prefix if base is 0 or 16,
343  * followed by numeric digits appropriate for base.
344  * @param end A pointer to the end of the valid character in buf. If
345  * not NULL, it is set to the first invalid character in buf.
346  * @param base A numeric base in the range between 2 and 36 inclusive,
347  * or 0. If base is zero, buf will be treated as base ten unless its
348  * digits are prefixed with '0x', in which case it will be treated as
349  * base 16.
350  * @return The numeric value of the string. On overflow, errno is set
351  * to ERANGE. On success, errno is set to 0.
352  */
353 APR_DECLARE(apr_int64_t) apr_strtoi64(const char *buf, char **end, int base);
354 
355 /**
356  * parse a base-10 numeric string into a 64-bit numeric value.
357  * Equivalent to apr_strtoi64(buf, (char**)NULL, 10).
358  * @param buf The string to parse
359  * @return The numeric value of the string. On overflow, errno is set
360  * to ERANGE. On success, errno is set to 0.
361  */
362 APR_DECLARE(apr_int64_t) apr_atoi64(const char *buf);
363 
364 /**
365  * Format a binary size (magnitiudes are 2^10 rather than 10^3) from an apr_off_t,
366  * as bytes, K, M, T, etc, to a four character compacted human readable string.
367  * @param size The size to format
368  * @param buf The 5 byte text buffer (counting the trailing null)
369  * @return The buf passed to apr_strfsize()
370  * @remark All negative sizes report ' - ', apr_strfsize only formats positive values.
371  */
372 APR_DECLARE(char *) apr_strfsize(apr_off_t size, char *buf);
373 
374 /** @} */
375 
376 #ifdef __cplusplus
377 }
378 #endif
379 
380 #endif /* !APR_STRINGS_H */