string(3)						     Library Functions Manual							 string(3)

NAME

       strcat, strcmp, strcpy, strdup - Perform operations on strings

LIBRARY

       Standard C Library (libc.so, libc.a)

SYNOPSIS

       #include <string.h>

       char *strcat(
	       char *s1,
	       const char *s2);

       int strcmp(
	       const char *s1,
	       const char *s2);

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

       char *strdup(
	       const char *s1);

STANDARDS

       Interfaces documented on this reference page conform to industry standards as follows:

       strcat(), strcmp(), strcpy():  XSH4.2

       strdup():  XSH4.2

       Refer to the standards(5) reference page for more information about industry standards and associated tags.

PARAMETERS

       In strcat(), specifies the destination string for appending; in strcmp(), specifies the first of two strings to compare; in strcpy(), spec-
       ifies the destination string for the copying; and in strdup(), specifies the string to be duplicated.  In strcat(), specifies the string to
       be  appended to s1; in strcmp(), specifies the second of two strings to compare; and in strcpy(), specifies the source string for the copy-
       ing.

									  Note
       [Tru64 UNIX]  If you pass a NULL pointer as one of the const char * or char * parameters of a string manipulation  function,  the  function
       generates  a  segmentation  violation.	To avoid the segmentation violation and cause the function to return zero, change the NULL pointer
       treatment for the process before issuing the call to the  string  manipulation  function,  as  follows:	Include  the  system  header  file
       sys/uswitch.h.  Call the uswitch function, as described in the uswitch(2) reference page.

       The following program illustrates this procedure:

       #include <stdio.h> #include <sys/types.h> #include <sys/uswitch.h>

       main() {
	       size_t  retval;
	       int     uswitch_val;

	       uswitch_val = uswitch(USC_GET,0);
	       uswitch(USC_SET, uswitch_val | USW_NULLP);
	       retval = strdup(NULL);

DESCRIPTION

       The  strcat()  function appends a copy of the string pointed to by the s2 parameter (including the terminating null byte) to the end of the
       string pointed to by the s1 parameter.  The initial byte of s2 overwrites the null byte at the end of the string pointed to  by	s1.   When
       operating on overlapping strings, the behavior of this function is unreliable.

       The  strcmp()  function	compares  the  string  pointed to by the s1 parameter to the string pointed to by the s2 parameter.  The sign of a
       nonzero value returned by strcmp() is determined by the sign of the difference between the values of the first pair of bytes  (both  inter-
       preted as unsigned char) that differ in the two compared objects.

       The  strcmp()  function compares strings based on the machine collating order. It does not use the locale-dependent sorting order.  Use the
       strcoll() or wcscoll() functions for locale-dependent sorting.

       The strcpy() function copies the string pointed to by the s2 parameter (including the terminating null byte) to the location pointed to	by
       the s1 parameter.  When operating on overlapping strings, the behavior of this function is unreliable.

       The  strdup() function returns a pointer to a new string that is an exact duplicate of the string pointed to by the s1 parameter.  The mal-
       loc() function is used to allocate space for the new string.

RETURN VALUES

       On successful completion, the  strcat(), strcpy(), and strdup() functions return a pointer to the resulting string. Otherwise, these  func-
       tions return a null pointer.  The strdup() function sets errno to indicate the error.

       On  successful completion, the strcmp() function returns an integer whose value is greater than, equal to, or less than 0 (zero), according
       to whether the s1 string is greater than, equal to, or less than the s2 string.

ERRORS

       If the strdup() function fails, errno may be set to the following value: Insufficient storage space is available.

RELATED INFORMATION

       Functions: malloc(3), memccpy(3), setlocale(3), strchr(3), strcoll(3), strlen(3), strncasecmp(3), strncat(3), strncmp(3), strncpy(3), strp-
       brk(3), strspn(3), strtok(3), strstr(3), strxfrm(3), swab(3), uswitch(2), wcscat(3), wcscmp(3), wcscpy(3)

       Standards: standards(5) delim off

																	 string(3)