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strncpy()

Copy a string, to a maximum length

Synopsis:

#include <string.h>

char* strncpy( char* dst,
               const char* src,
               size_t n );

Library:

libc

Description:

The strncpy() function copies no more than n characters from the string pointed to by src into the array pointed to by dst.


Note: Copying of overlapping objects isn't guaranteed to work properly. See the memmove() function if you wish to copy objects that overlap.

If the string pointed to by src is shorter than n characters, null characters are appended to the copy in the array pointed to by dst, until n characters in all have been written. If the string pointed to by src is longer than n characters, then the result isn't terminated by a null character.

Returns:

The value of dst.

Examples:

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

int main( void )
  {
    char buffer[15];

    printf( "%s\n", strncpy( buffer, "abcdefg", 10 ) );
    printf( "%s\n", strncpy( buffer, "1234567",  6 ) );
    printf( "%s\n", strncpy( buffer, "abcdefg",  3 ) );
    printf( "%s\n", strncpy( buffer, "*******",  0 ) );
    return EXIT_SUCCESS;
  }

produces the output:

abcdefg
123456g
abc456g
abc456g

Classification:

ANSI

Safety:
Cancellation point No
Interrupt handler Yes
Signal handler Yes
Thread Yes

See also:

strcpy(), strdup()


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