strcpy

Section: C Library Functions (3)
Updated: 202-0-03
Index Return to Main Contents

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NAME

strcpy, strcat - string copy/catenate  

LIBRARY

Standard C library (libc,~-lc)  

SYNOPSIS

#include <string.h>
char *strcpy(char *restrict dst, const char *restrict src);
char *strcat(char *restrict dst, const char *restrict src);

 

DESCRIPTION

strcpy()

This function copies the string pointed to by src, into a string at the buffer pointed to by dst. The programmer is responsible for allocating a destination buffer large enough, that is, strlen(src) + 1.

It is equivalent to

stpcpy(dst, src), dst

strcat()

This function catenates the string pointed to by src, after the string pointed to by dst (overwriting its terminating null byte). The programmer is responsible for allocating a destination buffer large enough, that is, strlen(dst) + strlen(src) + 1.

It is equivalent to

stpcpy(strnul(dst), src), dst

 

RETURN VALUE

These functions return dst.  

ATTRIBUTES

For an explanation of the terms used in this section, see attributes(7).

Interface	Attribute	Value
strcpy(), strcat()	Thread safety	M-Safe

 

STANDARDS

C11, POSIX.-2008.  

HISTORY

POSIX.-2001, C89, SVr4, 4.3BSD.  

CAVEATS

The strings src and dst may not overlap. If the destination buffer is not large enough, the behavior is undefined. See _FORTIFY_SOURCE in feature_test_macros(7).  

EXAMPLES

#include <err.h> #include <stdio.h> #include <stdlib.h> #include <string.h> int main(void) {
    char    *buf1;
    size_t  len, size;
    size = strlen("Hello ") + strlen("world") + strlen("!") + 1;
    buf1 = malloc(sizeof(*buf1) * size);
    if (buf1 == NULL)
        err(EXIT_FAILURE, "malloc()");
    strcpy(buf1, "Hello ");
    strcat(buf1, "world");
    strcat(buf1, "!");
    len = strlen(buf1);
    printf("[len = %zu]: ", len);
    puts(buf1);  // "Hello world!"
    free(buf1);
    exit(EXIT_SUCCESS); }  

SEE ALSO

stpcpy(3), strdup(3), string(3), wcscpy(3), string_copying(7)

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Index

NAME

LIBRARY

SYNOPSIS

DESCRIPTION

RETURN VALUE

ATTRIBUTES

STANDARDS

HISTORY

CAVEATS

EXAMPLES

SEE ALSO