strcpy - Man Page
copy a string and return a pointer to the end of the result
Prolog
This manual page is part of the POSIX Programmer's Manual. The Linux implementation of this interface may differ (consult the corresponding Linux manual page for details of Linux behavior), or the interface may not be implemented on Linux.
Synopsis
#include <string.h> char *stpcpy(char *restrict s1, const char *restrict s2); char *strcpy(char *restrict s1, const char *restrict s2);
Description
For strcpy(): 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.1-2017 defers to the ISO C standard.
The 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.
Return Value
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.
The following sections are informative.
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
The Base Definitions volume of POSIX.1-2017, <string.h>
Copyright
Portions of this text are reprinted and reproduced in electronic form from IEEE Std 1003.1-2017, Standard for Information Technology -- Portable Operating System Interface (POSIX), The Open Group Base Specifications Issue 7, 2018 Edition, Copyright (C) 2018 by the Institute of Electrical and Electronics Engineers, Inc and The Open Group. In the event of any discrepancy between this version and the original IEEE and The Open Group Standard, the original IEEE and The Open Group Standard is the referee document. The original Standard can be obtained online at http://www.opengroup.org/unix/online.html .
Any typographical or formatting errors that appear in this page are most likely to have been introduced during the conversion of the source files to man page format. To report such errors, see https://www.kernel.org/doc/man-pages/reporting_bugs.html .
Referenced By
localeconv(3p), string.h(0p), strncpy(3p), wcscpy(3p).