Watcom C Library Reference : atexit, atof, atoi, atol

 

 

WATCOM C Library Reference : atexit, atof, atoi, atol

 

 

 

 

atexit

 

Synopsis : #include <stdlib.h> 

              int atexit( void (*func) (void) );

Description : The atexit function is passed the address of function func to be called when the program terminates normally. Successive calls to atexit create a list of functions that will be executed on a "last-in, first-out" basis. No more than 32 functions can be registered with the atexit function.

The functions have no parameters and do not return values.

Returns : The atexit function returns zero if the registration succeeds, non-zero if it fails.

See Also : abort, -exit, exit

Example :

#include <stdio.h> 

#include <stdlib.h>
void main( )

{
    void func1 (void), func2 (void), func3 (void);

    atexit( func1 );

    atexit( func2 );

    atexit( func3 );

    printf( "Do this first.\n" );

}

void func1 (void) { printf( "last.\n" ); }
void func2 (void) { printf( "this " ); }
void func3 (void) { printf( "Do " ); }

 

produces the following :

Do this first. 

Do this last.

Classification : ANSI
Systems : All

 

 

 

atof

 

Synopsis : #include <stdlib.h> 

              double atof( const char *ptr );

Description : The atof function converts the string pointed to by ptr to double representation. It equivalent to

    strtod( ptr. (char **)NULL )

Returns : The atof function returns the converted value. Zero is returned when the input string cannot be converted. When an error has occurred, errno contains a value indicating the type of error that has been detected.

See Also : sscanf, strtod

Example :
#include <stdlib.h>
void main( )

{
    double x;
    x = atof( "3.1415926" );
}

 

 

Classification : ANSI
Systems : All

 

 

atoi

 

Synopsis : #include <stdlib.h> 

              int atoi ( const char *ptr );

Description : The atoi function converts the string pointed to by ptr to int representation.

Returns : The atoi function returns the converted value.

See Also : sscanf, strtol

Example :
#include <stdlib.h>
void main( )

{
    int x;
    x = atoi( "-289" );

}

 

 

Classification : ANSI
Systems : All

 

 

 

atol

 

Synopsis : #include <stdlib.h> 

              long int atol( const char *ptr );

Description : The atol function converts the string pointed to by ptr to long int representation.

Returns : The atol function returns the converted value.

See Also : sscanf, strtol

Example :
#include <stdlib.h>
void main( )

{
    long int x;
    x = atol( "-289" );

}

 

Classification : ANSI
Systems : All

 

 

 

 

 

 

This manual describes the WATCOM C library for DOS, Windows, and OS/2, It includes the Standard C Library (as defined in the ANSI C Standard).

 

WATCOM C Language Reference manual describes the ANSI C Programming language and extensions to it which are supported by WATCOM C/C++ (32bit)