memfil

memfil

Fill a Block of Memory with a Multicharacter String

Portability: SAS/C extension

SYNOPSIS
DESCRIPTION
RETURN VALUE
CAUTION
IMPLEMENTATION
EXAMPLE
RELATED FUNCTIONS
SEE ALSO

SYNOPSIS

#include <lcstring.h>

void *memfil(void *to, const void *from, size_t n,
             size_t len);

DESCRIPTION

memfil fills a block of memory (indicated by to ) with the contents of the array from . The argument n specifies the length of the area to be filled, while len specifies the size of the fill sequence. The area length does not have to be evenly divisible by the string length, in which case only a portion of the sequence is included in the final copy. Null characters in the fill sequence are treated like any other character.

RETURN VALUE

memfil returns the address of the to area.

CAUTION

The third argument to memfil has type size_t . If a negative number is passed, massive overlaying of memory occurs. (The fourth argument also has type size_t , but specification of a negative value here may produce incorrect results, but overlaying of memory will not occur.)

If the fill string and the target area overlap, the effect of memfil is undefined. If the string length is 0, the target area is not changed.

IMPLEMENTATION

memfil uses the MVCL instruction to propagate characters through memory. MVCL also copies the fill string to the target unless the fill string is longer than 256 bytes, in which case memcpy is called to do this.

EXAMPLE

#include <lcstring.h>

int minus2 = -2;
int values[100] [100];

   /* Set all array elements to -2. */
memfil(values, &minus2, sizeof(values), sizeof(int));

RELATED FUNCTIONS

memset

SEE ALSO

String Utility Functions

Chapter Contents
Previous
Next
Top of Page