STRDUP(3) Library Functions Manual STRDUP(3)

NAME

strdup, strndupsave a copy of a string

SYNOPSIS

#include <string.h>
char *
strdup(const char *s);
char *
strndup(const char *s, size_t maxlen);

DESCRIPTION

The strdup() function allocates sufficient memory for a copy of the string s, does the copy, and returns a pointer to it. The pointer may subsequently be used as an argument to the function free(3).
The strndup() function behaves similarly to strdup but only copies up to maxlen characters from s. The resulting string is always NUL-terminated.
If the memory allocation fails, NULL is returned.

EXAMPLES

The following will point p to an allocated area of memory containing the NUL-terminated string “foobar”:
char *p; 
 
p = strdup("foobar"); 
if (p == NULL) 
	err(1, NULL);

ERRORS

The strdup() and strndup() functions may fail and set the external variable errno for any of the errors specified for the library function malloc(3).

SEE ALSO

free(3), malloc(3), strcpy(3), strlcpy(3), strlen(3), wcsdup(3)

STANDARDS

The strdup() and strndup() functions conform to IEEE Std 1003.1-2008 (“POSIX.1”).

HISTORY

A strdup() macro was first used in the 4.1cBSD debugger, dbx. It was rewritten as a C function for the 4.3BSD inetd(8) and first appeared in the C library of 4.3BSD-Reno. The strndup() function appeared in glibc 2.0, was reimplemented for NetBSD 4.0, and ported to OpenBSD 4.8.
December 1, 2015 OpenBSD 6.1