strncat

 

C

Language

Standard Library

Type support

Dynamic memory management

Error handling

Program utilities

Date and time utilities

Strings library

Algorithms

Numerics

Input/output support

Localization support

Thread support (C11)

Atomic operations (C11)

 

Strings library

Byte strings

Multibyte strings

Wide strings

 

Null-terminated byte strings

Functions
Character manipulation
isalnum isalpha islower isupper isdigit isxdigit isblank (C99)	iscntrl isgraph isspace isprint ispunct tolower toupper
Conversions to numeric formats
atof atoiatolatoll strtolstrtoll	strtoulstrtoull strtofstrtodstrtold
String manipulation
strcpy
strncpy
strcat
strncat
strxfrm
String examination
strlen strcmp strncmp strcoll strchr strrchr	strspn strcspn strpbrk strstr strtok
Memory manipulation
memchr
memcmp
memset
memcpy
memmove
Miscellaneous
strerror

 

Defined in header <string.h>
char *strncat( char          *dest, const char          *src, size_t count );		(until C99)
char *strncat( char *restrict dest, const char *restrict src, size_t count );		(since C99)

Appends a byte string pointed to by src to a byte string pointed to by dest. At most count characters from src are copied. The resulting byte string is null-terminated.

The destination byte string must have enough space for the contents of both dest and src plus the terminating null character, except that the size of src is limited to count.

The behavior is undefined if the strings overlap.

Parameters

dest	-	pointer to the null-terminated byte string to append to
src	-	pointer to the null-terminated byte string to copy from
count	-	maximum number of characters to copy

Return value

dest

Example

Run this code

#include <string.h> 
#include <stdio.h>
 
int main(void) 
{
    char str[50] = "Hello ";
    char str2[50] = "World!";
    strcat(str, str2);
    strncat(str, " Goodbye World!", 3);
    puts(str);
}

Output:

Hello World! Go

See also

strcat	concatenates two strings (function)
strcpy	copies one string to another (function)
C++ documentation for strncat