Convert
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These functions allow you to convert integer or real numbers to string or conversely. More...

Functions

EAPI int eina_convert_init (void)
 Initialize the eina convert internal structure.
EAPI int eina_convert_shutdown (void)
 Shut down the eina convert internal structures.
EAPI int eina_convert_itoa (int n, char *s)
 Convert an integer number to a string in decimal base.
EAPI int eina_convert_xtoa (unsigned int n, char *s)
 Convert an integer number to a string in hexadecimal base.
EAPI int eina_convert_dtoa (double d, char *des)
 Convert a double to a string.
EAPI Eina_Bool eina_convert_atod (const char *src, int length, long long *m, long *e)
 Convert a string to a double.

Variables

EAPI Eina_Error EINA_ERROR_CONVERT_P_NOT_FOUND
 Error identifier corresponding to string not containing 'p'.
EAPI Eina_Error EINA_ERROR_CONVERT_0X_NOT_FOUND
 Error identifier corresponding to string not containing '0x'.
EAPI Eina_Error EINA_ERROR_CONVERT_OUTRUN_STRING_LENGTH
 Error identifier corresponding to length of the string being too small.

Detailed Description

These functions allow you to convert integer or real numbers to string or conversely.

To use these function, you have to call eina_convert_init() first, and eina_convert_shutdown() when they are not used anymore.

Conversion from integer to string

To convert an integer to a string in the decimal base, eina_convert_itoa() should be used. If the hexadecimal base is wanted, eina_convert_xtoa() should be used. They all need a bufffer sufficiently large to store all the cyphers.

Here is an exemple of use:

 #include <stdlib.h>
 #include <stdio.h>

 #include <eina_convert.h>

 int main(void)
 {
    char *tmp[128];

    if (!eina_convert_init())
    {
        printf ("Error during the initialization of eina_convert module\n");
        return EXIT_FAILURE;
    }

    eina_convert_itoa(45, tmp);
    printf("value: %s\n", tmp);

    eina_convert_xtoa(0xA1, tmp);
    printf("value: %s\n", tmp);

    eina_convert_shutdown();

    return EXIT_SUCCESS;
 }

Compile this code with the following commant:

 gcc -Wall -o test_eina_convert test_eina.c `pkg-config --cflags --libs eina`
Note:
The alphabetical cyphers are in lower case.

Conversion double / string

To convert a double to a string, eina_convert_dtoa() should be used. Like with the integer functions, a buffer must be used. The resulting string ghas the following format (which is the result obtained with snprintf() and the %a modifier):

 [-]0xh.hhhhhp[+-]e

To convert a string to a double, eina_convert_atod() should be used. The format of the string must be as above. Then, the double has the following mantiss and exponent:

 mantiss  : [-]hhhhhh
 exponent : 2^([+-]e - 4 * n)

with n being number of cypers after the point in the string format. To obtain the double number from the mantiss and exponent, use ldexp().

Here is an exemple of use:

 #include <stdlib.h>
 #include <stdio.h>

 #include <eina_convert.h>

 int main(void)
 {
    char     *tmp[128];
    long long int m = 0;
    long int  e = 0;
    doule     r;

    if (!eina_convert_init())
    {
        printf ("Error during the initialization of eina_convert module\n");
        return EXIT_FAILURE;
    }

    eina_convert_dtoa(40.56, tmp);
    printf("value: %s\n", tmp);

    eina_convert_atod(tmp, 128, &m, &e);
    r = ldexp((double)m, e);
    printf("value: %s\n", tmp);

    eina_convert_shutdown();

    return EXIT_SUCCESS;
 }

Compile this code with the same command as above.


Function Documentation

EAPI int eina_convert_init ( void   ) 

Initialize the eina convert internal structure.

Returns:
1 or greater on success, 0 on error.

This function sets up the error module of Eina and registers the errors EINA_ERROR_CONVERT_0X_NOT_FOUND, EINA_ERROR_CONVERT_P_NOT_FOUND and EINA_ERROR_CONVERT_OUTRUN_STRING_LENGTH. It is also called by eina_init(). It returns 0 on failure, otherwise it returns the number of times it has already been called.

References eina_error_init(), and eina_error_msg_register().

EAPI int eina_convert_shutdown ( void   ) 

Shut down the eina convert internal structures.

Returns:
0 when the convert module is completely shut down, 1 or greater otherwise.

This function just shuts down the error module. It is also called by eina_shutdown(). It returns 0 when it is called the same number of times than eina_convert_init().

References eina_error_shutdown().

EAPI int eina_convert_itoa ( int  n,
char *  s 
)

Convert an integer number to a string in decimal base.

Parameters:
n The integer to convert.
s The buffer to store the converted integer.
Returns:
The length of the string, including the nul terminated character.

This function converts n to a nul terminated string. The converted string is in decimal base. As no check is done, s must be a buffer that is sufficiently large to store the integer.

The returned value is the length os the string, including the nul terminated character.

Referenced by eina_convert_dtoa().

EAPI int eina_convert_xtoa ( unsigned int  n,
char *  s 
)

Convert an integer number to a string in hexadecimal base.

Parameters:
n The integer to convert.
s The buffer to store the converted integer.
Returns:
The length of the string, including the nul terminated character.

This function converts n to a nul terminated string. The converted string is in hexadecimal base and the alphabetical cyphers are in lower case. As no check is done, s must be a buffer that is sufficiently large to store the integer.

The returned value is the length os the string, including the nul terminated character.

EAPI int eina_convert_dtoa ( double  d,
char *  des 
)

Convert a double to a string.

Parameters:
d The double to convert.
des The destination buffer to store the converted double.
Returns:
EINA_TRUE on success, EINA_FALSE otherwise.

This function converts the double d to a string. The string is stored in the buffer pointed by des and must be sufficiently large to contain the converted double. The returned string is terminated and has the following format:

 [-]0xh.hhhhhp[+-]e

where the h are the hexadecimal cyphers of the mantiss and e the exponent (a decimal number).

The returned value is the length of the string, including the nul character.

References eina_convert_itoa(), and EINA_FALSE.

EAPI Eina_Bool eina_convert_atod ( const char *  src,
int  length,
long long *  m,
long *  e 
)

Convert a string to a double.

Parameters:
src The string to convert.
length The length of the string.
m The mantisse.
e The exponent.
Returns:
EINA_TRUE on success, EINA_FALSE otherwise.

This function converts the string s of length length that represent a double in hexadecimal base to a double. It is used to replace the use of snprintf() with the %a modifier, which is missing on some platform (like Windows (tm) or OpenBSD).

The string must have the following format:

 [-]0xh.hhhhhp[+-]e

where the h are the hexadecimal cyphers of the mantiss and e the exponent (a decimal number). If n is the number of cypers after the point, the returned mantiss and exponents are:

 mantiss  : [-]hhhhhh
 exponent : 2^([+-]e - 4 * n)

The mantiss and exponent are stored in the buffers pointed respectively by m and e.

If the string is invalid, the error is set to:

In those cases, EINA_FALSE is returned, otherwise EINA_TRUE is returned.

References EINA_ERROR_PDBG, eina_error_set(), EINA_FALSE, and EINA_TRUE.