strncat -- Concatenate Strings

Format

#include <string.h>
char *strncat(char *string1, const char *string2, size_t count);

Language Level: ANSI, POSIX, XPG4
strncat appends the first count characters of string2 to string1 and ends the resulting string with a null character (\0). If count is greater than the length of string2, the length of string2 is used in place of count.

The strncat function operates on null-terminated strings. The string argument to the function should contain a null character (\0) marking the end of the string.

Return Value
strncat returns a pointer to the joined string (string1).

Example
This example demonstrates the difference between strcat and strncat. strcat appends the entire second string to the first, whereas strncat appends only the specified number of characters in the second string to the first.

#include <stdio.h>
#include <string.h>
#define SIZE 40
int main(void)
{
  char buffer1[SIZE] = "computer";
  char * ptr;
  /* Call strcat with buffer1 and " program" */
  ptr = strcat( buffer1, " program" );
  printf( "strcat : buffer1 = \"%s\"\n", buffer1 );
  /* Reset buffer1 to contain just the string "computer" again */
  memset( buffer1, '\0', sizeof( buffer1 ));
  ptr = strcpy( buffer1, "computer" );
  /* Call strncat with buffer1 and " program" */
  ptr = strncat( buffer1, " program", 3 );
  printf( "strncat: buffer1 = \"%s\"\n", buffer1 );
  return 0;
  /*************************************************************
     The output should be:
     strcat : buffer1 = "computer program"
     strncat : buffer1 = "computer pr"
  *************************************************************/
}


strcat -- Concatenate Strings
strncmp -- Compare Strings
strncpy -- Copy Strings
strnicmp -- Compare Strings Without Case Sensitivity
strpbrk -- Find Characters in String
strrchr -- Find Last Occurrence of Character in String
strspn -- Search Strings
wcscat -- Concatenate Wide-Character Strings
wcsncat -- Concatenate Wide-Character Strings
<string.h>