NAME

stpcpy, strcpy — copy a string

SYNOPSIS

#include <string.h>



[CX] char *stpcpy(char *restrict s1, const char *restrict s2);

char *strcpy(char *restrict s1, const char *restrict s2);

DESCRIPTION

For strcpy(): ^[CX]  The functionality described on this reference page is aligned with the ISO C standard. Any conflict between the requirements described here and the ISO C standard is unintentional. This volume of POSIX.1-2024 defers to the ISO C standard.

The ^[CX] stpcpy()  and strcpy() functions shall copy the string pointed to by s2 (including the terminating NUL character) into the array pointed to by s1.

If copying takes place between objects that overlap, the behavior is undefined.

^[CX] The strcpy() and stpcpy() functions shall not change the setting of errno on valid input.

RETURN VALUE

^[CX] The stpcpy() function shall return a pointer to the terminating NUL character copied into the s1 buffer.

The strcpy() function shall return s1.

No return values are reserved to indicate an error.

ERRORS

No errors are defined.

EXAMPLES

Construction of a Multi-Part Message in a Single Buffer

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


int
main (void)
{
    char buffer [10];
    char *name = buffer;


    name = stpcpy (stpcpy (stpcpy (name, "ice"),"-"), "cream");
    puts (buffer);
    return 0;
}

Initializing a String

The following example copies the string "----------" into the permstring variable.

#include <string.h>
...
static char permstring[11];
...
strcpy(permstring, "----------");
...

Storing a Key and Data

The following example allocates space for a key using malloc() then uses strcpy() to place the key there. Then it allocates space for data using malloc(), and uses strcpy() to place data there. (The user-defined function dbfree() frees memory previously allocated to an array of type struct element *.)

#include <string.h>
#include <stdlib.h>
#include <stdio.h>
...
/* Structure used to read data and store it. */
struct element {
    char *key;
    char *data;
};


struct element *tbl, *curtbl;
char *key, *data;
int count;
...
void dbfree(struct element *, int);
...
if ((curtbl->key = malloc(strlen(key) + 1)) == NULL) {
    perror("malloc"); dbfree(tbl, count); return NULL;
}
strcpy(curtbl->key, key);


if ((curtbl->data = malloc(strlen(data) + 1)) == NULL) {
    perror("malloc"); free(curtbl->key); dbfree(tbl, count); return NULL;
}
strcpy(curtbl->data, data);
...

APPLICATION USAGE

Character movement is performed differently in different implementations. Thus, overlapping moves may yield surprises.

This version is aligned with the ISO C standard; this does not affect compatibility with XPG3 applications. Reliable error detection by this function was never guaranteed.

RATIONALE

None.

FUTURE DIRECTIONS

None.

SEE ALSO

strncpy , wcscpy

XBD <string.h>

CHANGE HISTORY

First released in Issue 1. Derived from Issue 1 of the SVID.

Issue 6

The strcpy() prototype is updated for alignment with the ISO/IEC 9899:1999 standard.

Issue 7

The stpcpy() function is added from The Open Group Technical Standard, 2006, Extended API Set Part 1.

Issue 8

Austin Group Defect 448 is applied, adding a requirement that strcpy() and stpcpy() do not change the setting of errno on valid input.

Austin Group Defect 1787 is applied, changing the NAME section.