Group PJ_PSTR

group PJ_PSTR

This module provides string manipulation API.

PJLIB String is NOT Null Terminated!

That is the first information that developers need to know. Instead of using normal C string, strings in PJLIB are represented as pj_str_t structure below:

There are some advantages of using this approach:

the string can point to arbitrary location in memory even if the string in that location is not null terminated. This is most usefull for text parsing, where the parsed text can just point to the original text in the input. If we use C string, then we will have to copy the text portion from the input to a string variable.
because the length of the string is known, string copy operation can be made more efficient.

Most of APIs in PJLIB that expect or return string will represent the string as pj_str_t instead of normal C string.

Examples

For some examples, please see:

String test: pjlib/src/pjlib-test/string.c

Defines

PJ_CHECK_TRUNC_STR(ret, str, len)

Check if a string is truncated and if yes, put a suffix of “..” to indicate the truncation. This macro is used to check the result of pj_ansi_snprintf().

Parameters:

ret – The return value of pj_ansi_snprintf().
str – The string.
len – The length of the string buffer.

strnicmp_alnum

Perform lowercase comparison to the strings which consists of only alnum characters. More over, it will only return non-zero if both strings are not equal, not the usual negative or positive value.

If non-alnum inputs are given, then the function may mistakenly treat two strings as equal.

Parameters:

str1 – The string to compare.
str2 – The string to compare.
len – The length to compare.

Returns:

0 if str1 is equal to str2
(-1) if not equal.

pj_stricmp_alnum

Perform lowercase comparison to the strings which consists of only alnum characters. More over, it will only return non-zero if both strings are not equal, not the usual negative or positive value.

If non-alnum inputs are given, then the function may mistakenly treat two strings as equal.

Parameters:

str1 – The string to compare.
str2 – The string to compare.

Returns:

0 if str1 is equal to str2
(-1) if not equal.

Functions

pj_str_t pj_str(char *str)

Create string initializer from a normal C string.

Parameters:: str – Null terminated string to be stored.
Returns:: pj_str_t.

const pj_str_t *pj_cstr(pj_str_t *str, const char *s)

Create constant string from normal C string.

Parameters:

str – The string to be initialized.
s – Null terminated string.

Returns:

pj_str_t.

pj_str_t *pj_strset(pj_str_t *str, char *ptr, pj_size_t length)

Set the pointer and length to the specified value.

Parameters:

str – the string.
ptr – pointer to set.
length – length to set.

Returns:

the string.

pj_str_t *pj_strset2(pj_str_t *str, char *src)

Set the pointer and length of the string to the source string, which must be NULL terminated.

Parameters:

str – the string.
src – pointer to set.

Returns:

the string.

pj_str_t *pj_strset3(pj_str_t *str, char *begin, char *end)

Set the pointer and the length of the string.

Parameters:

str – The target string.
begin – The start of the string.
end – The end of the string.

Returns:

the target string.

pj_str_t *pj_strassign(pj_str_t *dst, pj_str_t *src)

Assign string.

Parameters:

dst – The target string.
src – The source string.

Returns:

the target string.

pj_str_t *pj_strcpy(pj_str_t *dst, const pj_str_t *src)

Copy string contents.

Parameters:

dst – The target string.
src – The source string.

Returns:

the target string.

pj_str_t *pj_strcpy2(pj_str_t *dst, const char *src)

Copy string contents.

Parameters:

dst – The target string.
src – The source string.

Returns:

the target string.

pj_str_t *pj_strncpy(pj_str_t *dst, const pj_str_t *src, pj_ssize_t max)

Copy source string to destination up to the specified max length.

Parameters:

dst – The target string.
src – The source string.
max – Maximum characters to copy.

Returns:

the target string.

pj_str_t *pj_strncpy_with_null(pj_str_t *dst, const pj_str_t *src, pj_ssize_t max)

Copy source string to destination up to the specified max length, and NULL terminate the destination. If source string length is greater than or equal to max, then max-1 will be copied.

Parameters:

dst – The target string.
src – The source string.
max – Maximum characters to copy.

Returns:

the target string.

pj_str_t *pj_strdup(pj_pool_t *pool, pj_str_t *dst, const pj_str_t *src)

Duplicate string.

Parameters:

pool – The pool.
dst – The string result.
src – The string to duplicate.

Returns:

the string result.

pj_str_t *pj_strdup_with_null(pj_pool_t *pool, pj_str_t *dst, const pj_str_t *src)

Duplicate string and NULL terminate the destination string.

Parameters:

pool – The pool.
dst – The string result.
src – The string to duplicate.

Returns:

The string result.

pj_str_t *pj_strdup2(pj_pool_t *pool, pj_str_t *dst, const char *src)

Duplicate string.

Parameters:

pool – The pool.
dst – The string result.
src – The string to duplicate.

Returns:

the string result.

pj_str_t *pj_strdup2_with_null(pj_pool_t *pool, pj_str_t *dst, const char *src)

Duplicate string and NULL terminate the destination string.

Parameters:

pool – The pool.
dst – The string result.
src – The string to duplicate.

Returns:

The string result.

pj_str_t pj_strdup3(pj_pool_t *pool, const char *src)

Duplicate string.

Parameters:

pool – The pool.
src – The string to duplicate.

Returns:

the string result.

pj_size_t pj_strlen(const pj_str_t *str)

Return the length of the string.

Parameters:: str – The string.
Returns:: the length of the string.

const char *pj_strbuf(const pj_str_t *str)

Return the pointer to the string data.

Parameters:: str – The string.
Returns:: the pointer to the string buffer.

int pj_strcmp(const pj_str_t *str1, const pj_str_t *str2)

Compare strings.

Parameters:

str1 – The string to compare.
str2 – The string to compare.

Returns:

< 0 if str1 is less than str2
0 if str1 is identical to str2
> 0 if str1 is greater than str2

int pj_strcmp2(const pj_str_t *str1, const char *str2)

Compare strings.

Parameters:

str1 – The string to compare.
str2 – The string to compare.

Returns:

< 0 if str1 is less than str2
0 if str1 is identical to str2
> 0 if str1 is greater than str2

int pj_strncmp(const pj_str_t *str1, const pj_str_t *str2, pj_size_t len)

Compare strings.

Parameters:

str1 – The string to compare.
str2 – The string to compare.
len – The maximum number of characters to compare.

Returns:

< 0 if str1 is less than str2
0 if str1 is identical to str2
> 0 if str1 is greater than str2

int pj_strncmp2(const pj_str_t *str1, const char *str2, pj_size_t len)

Compare strings.

Parameters:

str1 – The string to compare.
str2 – The string to compare.
len – The maximum number of characters to compare.

Returns:

< 0 if str1 is less than str2
0 if str1 is identical to str2
> 0 if str1 is greater than str2

int pj_stricmp(const pj_str_t *str1, const pj_str_t *str2)

Perform case-insensitive comparison to the strings.

Parameters:

str1 – The string to compare.
str2 – The string to compare.

Returns:

< 0 if str1 is less than str2
0 if str1 is equal to str2
> 0 if str1 is greater than str2

int pj_stricmp2(const pj_str_t *str1, const char *str2)

Perform case-insensitive comparison to the strings.

Parameters:

str1 – The string to compare.
str2 – The string to compare.

Returns:

< 0 if str1 is less than str2
0 if str1 is identical to str2
> 0 if str1 is greater than str2

int pj_strnicmp(const pj_str_t *str1, const pj_str_t *str2, pj_size_t len)

Perform case-insensitive comparison to the strings.

Parameters:

str1 – The string to compare.
str2 – The string to compare.
len – The maximum number of characters to compare.

Returns:

< 0 if str1 is less than str2
0 if str1 is identical to str2
> 0 if str1 is greater than str2

int pj_strnicmp2(const pj_str_t *str1, const char *str2, pj_size_t len)

Perform case-insensitive comparison to the strings.

Parameters:

str1 – The string to compare.
str2 – The string to compare.
len – The maximum number of characters to compare.

Returns:

< 0 if str1 is less than str2
0 if str1 is identical to str2
> 0 if str1 is greater than str2

void pj_strcat(pj_str_t *dst, const pj_str_t *src)

Concatenate strings.

Parameters:

dst – The destination string.
src – The source string.

void pj_strcat2(pj_str_t *dst, const char *src)

Concatenate strings.

Parameters:

dst – The destination string.
src – The source string.

char *pj_strchr(const pj_str_t *str, int chr)

Finds a character in a string.

Parameters:

str – The string.
chr – The character to find.

Returns:

the pointer to first character found, or NULL.

pj_ssize_t pj_strspn(const pj_str_t *str, const pj_str_t *set_char)

Find the first index of character, in a string, that does not belong to a set of characters.

Parameters:

str – The string.
set_char – The string containing the set of characters.

Returns:

the index of the first character in the str that doesn’t belong to set_char. If str starts with a character not in set_char, return 0.

pj_ssize_t pj_strspn2(const pj_str_t *str, const char *set_char)

Find the first index of character, in a string, that does not belong to a set of characters.

Parameters:

str – The string.
set_char – The string containing the set of characters.

Returns:

the index of the first character in the str that doesn’t belong to set_char. If str starts with a character not in set_char, return 0.

pj_ssize_t pj_strcspn(const pj_str_t *str, const pj_str_t *set_char)

Find the first index of character, in a string, that belong to a set of characters.

Parameters:

str – The string.
set_char – The string containing the set of characters.

Returns:

the index of the first character in the str that belong to set_char. If no match is found, return the length of str.

pj_ssize_t pj_strcspn2(const pj_str_t *str, const char *set_char)

Find the first index of character, in a string, that belong to a set of characters.

Parameters:

str – The string.
set_char – The string containing the set of characters.

Returns:

the index of the first character in the str that belong to set_char. If no match is found, return the length of str.

pj_ssize_t pj_strtok(const pj_str_t *str, const pj_str_t *delim, pj_str_t *tok, pj_size_t start_idx)

Find tokens from a string using the delimiter.

Parameters:

str – The string.
delim – The string containing the delimiter. It might contain multiple character treated as unique set. If same character was found on the set, it will be skipped.
tok – The string containing the token.
start_idx – The search will start from this index.

Returns:

the index of token from the str, or the length of the str if the token is not found.

pj_ssize_t pj_strtok2(const pj_str_t *str, const char *delim, pj_str_t *tok, pj_size_t start_idx)

Find tokens from a string using the delimiter.

Parameters:

str – The string.
delim – The string containing the delimiter. It might contain multiple character treated as unique set. If same character was found on the set, it will be skipped.
tok – The string containing the token.
start_idx – The search will start from this index.

Returns:

the index of token from the str, or the length of the str if the token is not found.

char *pj_strstr(const pj_str_t *str, const pj_str_t *substr)

Find the occurence of a substring substr in string str.

Parameters:

str – The string to search.
substr – The string to search fo.

Returns:

the pointer to the position of substr in str, or NULL. Note that if str is not NULL terminated, the returned pointer is pointing to non-NULL terminated string.

char *pj_stristr(const pj_str_t *str, const pj_str_t *substr)

Performs substring lookup like pj_strstr() but ignores the case of both strings.

Parameters:

str – The string to search.
substr – The string to search fo.

Returns:

the pointer to the position of substr in str, or NULL. Note that if str is not NULL terminated, the returned pointer is pointing to non-NULL terminated string.

pj_str_t *pj_strltrim(pj_str_t *str)

Remove (trim) leading whitespaces from the string.

Parameters:: str – The string.
Returns:: the string.

pj_str_t *pj_strrtrim(pj_str_t *str)

Remove (trim) the trailing whitespaces from the string.

Parameters:: str – The string.
Returns:: the string.

pj_str_t *pj_strtrim(pj_str_t *str)

Remove (trim) leading and trailing whitespaces from the string.

Parameters:: str – The string.
Returns:: the string.

char *pj_create_random_string(char *str, pj_size_t length)

Initialize the buffer with some random string. Note that the generated string is not NULL terminated.

Parameters:

str – the string to store the result.
length – the length of the random string to generate.

Returns:

the string.

long pj_strtol(const pj_str_t *str)

Convert string to signed integer. The conversion will stop as soon as non-digit character is found or all the characters have been processed.

Parameters:: str – the string.
Returns:: the integer.

pj_status_t pj_strtol2(const pj_str_t *str, long *value)

Convert string to signed long integer. The conversion will stop as soon as non-digit character is found or all the characters have been processed.

Parameters:

str – the string.
value – Pointer to a long to receive the value.

Returns:

PJ_SUCCESS if successful. Otherwise: PJ_ETOOSMALL if the value was an impossibly long negative number. In this case *value will be set to LONG_MIN.

PJ_ETOOBIG if the value was an impossibly long positive number. In this case, *value will be set to LONG_MAX.

PJ_EINVAL if the input string was NULL, the value pointer was NULL or the input string could not be parsed at all such as starting with a character other than a ‘+’, ‘-’ or not in the ‘0’ - ‘9’ range. In this case, *value will be left untouched.

unsigned long pj_strtoul(const pj_str_t *str)

Convert string to unsigned integer. The conversion will stop as soon as non-digit character is found or all the characters have been processed.

Parameters:: str – the string.
Returns:: the unsigned integer.

unsigned long pj_strtoul2(const pj_str_t *str, pj_str_t *endptr, unsigned base)

Convert strings to an unsigned long-integer value. This function stops reading the string input either when the number of characters has exceeded the length of the input or it has read the first character it cannot recognize as part of a number, that is a character greater than or equal to base.

Parameters:

str – The input string.
endptr – Optional pointer to receive the remainder/unparsed portion of the input.
base – Number base to use.

Returns:

the unsigned integer number.

pj_status_t pj_strtoul3(const pj_str_t *str, unsigned long *value, unsigned base)

Convert string to unsigned long integer. The conversion will stop as soon as non-digit character is found or all the characters have been processed.

Parameters:

str – The input string.
value – Pointer to an unsigned long to receive the value.
base – Number base to use.

Returns:

PJ_SUCCESS if successful. Otherwise: PJ_ETOOBIG if the value was an impossibly long positive number. In this case, *value will be set to ULONG_MAX.

PJ_EINVAL if the input string was NULL, the value pointer was NULL or the input string could not be parsed at all such as starting with a character outside the base character range. In this case, *value will be left untouched.

pj_status_t pj_strtoul4(const pj_str_t *str, pj_uint_t *value, unsigned base)

Convert string to generic unsigned integer. The conversion will stop as soon as non-digit character is found or all the characters have been processed.

Parameters:

str – The input string.
value – Pointer to an unsigned integer to receive the value. The value will be a 64 bit unsigned integer if the system supports it, otherwise a 32 bit unsigned integer.
base – Number base to use.

Returns:

PJ_SUCCESS if successful. Otherwise: PJ_ETOOBIG if the value was an impossibly long positive number. In this case, *value will be set to ULLONG_MAX (for 64 bit) or ULONG_MAX (for 32 bit).

PJ_EINVAL if the input string was NULL, the value pointer was NULL or the input string could not be parsed at all such as starting with a character outside the base character range. In this case, *value will be left untouched.

float pj_strtof(const pj_str_t *str)

Convert string to float.

Parameters:: str – the string.
Returns:: the value.

int pj_utoa(unsigned long val, char *buf)

Utility to convert unsigned integer to string. Note that the string will be NULL terminated.

Parameters:

val – the unsigned integer value.
buf – the buffer

Returns:

the number of characters written

int pj_utoa2(pj_uint_t val, char *buf)

Utility to convert generic unsigned integer to string. Note that the string will be NULL terminated.

This function will take 64 bit unsigned integer if the system has one, otherwise it takes 32 bit unsigned integer.

Parameters:

val – the unsigned integer value.
buf – the buffer

Returns:

the number of characters written

int pj_utoa_pad(unsigned long val, char *buf, int min_dig, int pad)

Convert unsigned integer to string with minimum digits. Note that the string will be NULL terminated.

Parameters:

val – The unsigned integer value.
buf – The buffer.
min_dig – Minimum digits to be printed, or zero to specify no minimum digit.
pad – The padding character to be put in front of the string when the digits is less than minimum.

Returns:

the number of characters written.

int pj_utoa_pad2(pj_uint_t val, char *buf, int min_dig, int pad)

Convert generic unsigned integer to string with minimum digits. Note that the string will be NULL terminated.

This function will take 64 bit unsigned integer if the system has one, otherwise it takes 32 bit unsigned integer.

Parameters:

val – The unsigned integer value.
buf – The buffer.
min_dig – Minimum digits to be printed, or zero to specify no minimum digit.
pad – The padding character to be put in front of the string when the digits is less than minimum.

Returns:

the number of characters written.

void pj_bzero(void *dst, pj_size_t size)

Fill the memory location with zero.

Parameters:

dst – The destination buffer.
size – The number of bytes.

void *pj_memset(void *dst, int c, pj_size_t size)

Fill the memory location with value.

Parameters:

dst – The destination buffer.
c – Character to set.
size – The number of characters.

Returns:

the value of dst.

void *pj_memcpy(void *dst, const void *src, pj_size_t size)

Copy buffer.

Parameters:

dst – The destination buffer.
src – The source buffer.
size – The size to copy.

Returns:

the destination buffer.

void *pj_memmove(void *dst, const void *src, pj_size_t size)

Move memory.

Parameters:

dst – The destination buffer.
src – The source buffer.
size – The size to copy.

Returns:

the destination buffer.

int pj_memcmp(const void *buf1, const void *buf2, pj_size_t size)

Compare buffers.

Parameters:

buf1 – The first buffer.
buf2 – The second buffer.
size – The size to compare.

Returns:

negative, zero, or positive value.

void *pj_memchr(const void *buf, int c, pj_size_t size)

Find character in the buffer.

Parameters:

buf – The buffer.
c – The character to find.
size – The size to check.

Returns:

the pointer to location where the character is found, or NULL if not found.

int pj_ansi_strxcpy(char *dst, const char *src, pj_size_t dst_size)

Copy the string, or as much of it as fits, into the dest buffer. Regardless of whether all characters were copied, the destination buffer will be null terminated, unless dst_size is zero which in this case nothing will be written to dst and the function will return -PJ_ETOOBIG.

Parameters:

dst – The destination string.
src – The source string.
dst_size – The full size of the destination string buffer.

Returns:

The number of characters copied (not including the trailing NUL) or -PJ_ETOOBIG if the destination buffer wasn’t big enough, -PJ_EINVAL if the dst or src is NULL.

int pj_ansi_strxcpy2(char *dst, const pj_str_t *src, pj_size_t dst_size)

Same as pj_ansi_strxcpy() but takes pj_str_t as the source. If src contains null character, copying will stop at the first null character in src.

Parameters:

dst – The destination string.
src – The source string.
dst_size – The full size of the destination string buffer.

Returns:

The number of characters copied (not including the trailing NUL) or -PJ_ETOOBIG if the destination buffer wasn’t big enough, -PJ_EINVAL if the dst or src is NULL.

int pj_ansi_strxcat(char *dst, const char *src, pj_size_t dst_size)

Concatenate src, or as much of it as fits, into the dest buffer. Regardless of whether all characters were copied, the destination buffer will be null terminated, unless dst_size is zero which in this case nothing will be written to dst and the function will return -PJ_ETOOBIG.

Parameters:

dst – The destination string.
src – The source string.
dst_size – The full size of the destination string buffer.

Returns:

Final length of dst string (not including the trailing NUL) or -PJ_ETOOBIG if the destination buffer wasn’t big enough, -PJ_EINVAL if the dst or src is NULL.