strcoll(3p) [centos man page]
STRCOLL(3P) POSIX Programmer's Manual STRCOLL(3P) PROLOG
This manual page is part of the POSIX Programmer's Manual. The Linux implementation of this interface may differ (consult the correspond- ing Linux manual page for details of Linux behavior), or the interface may not be implemented on Linux. NAME
strcoll - string comparison using collating information SYNOPSIS
#include <string.h> int strcoll(const char *s1, const char *s2); DESCRIPTION
The strcoll() function shall compare the string pointed to by s1 to the string pointed to by s2, both interpreted as appropriate to the LC_COLLATE category of the current locale. The strcoll() function shall not change the setting of errno if successful. Since no return value is reserved to indicate an error, an application wishing to check for error situations should set errno to 0, then call strcoll(), then check errno. RETURN VALUE
Upon successful completion, strcoll() shall return an integer greater than, equal to, or less than 0, according to whether the string pointed to by s1 is greater than, equal to, or less than the string pointed to by s2 when both are interpreted as appropriate to the cur- rent locale. On error, strcoll() may set errno, but no return value is reserved to indicate an error. ERRORS
The strcoll() function may fail if: EINVAL The s1 or s2 arguments contain characters outside the domain of the collating sequence. The following sections are informative. EXAMPLES
Comparing Nodes The following example uses an application-defined function, node_compare(), to compare two nodes based on an alphabetical ordering of the string field. #include <string.h> ... struct node { /* These are stored in the table. */ char *string; int length; }; ... int node_compare(const void *node1, const void *node2) { return strcoll(((const struct node *)node1)->string, ((const struct node *)node2)->string); } ... APPLICATION USAGE
The strxfrm() and strcmp() functions should be used for sorting large lists. RATIONALE
None. FUTURE DIRECTIONS
None. SEE ALSO
strcmp(), strxfrm(), the Base Definitions volume of IEEE Std 1003.1-2001, <string.h> COPYRIGHT
Portions of this text are reprinted and reproduced in electronic form from IEEE Std 1003.1, 2003 Edition, Standard for Information Technol- ogy -- Portable Operating System Interface (POSIX), The Open Group Base Specifications Issue 6, Copyright (C) 2001-2003 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 . IEEE
/The Open Group 2003 STRCOLL(3P)
Check Out this Related Man Page
STRXFRM(3P) POSIX Programmer's Manual STRXFRM(3P) PROLOG
This manual page is part of the POSIX Programmer's Manual. The Linux implementation of this interface may differ (consult the correspond- ing Linux manual page for details of Linux behavior), or the interface may not be implemented on Linux. NAME
strxfrm - string transformation SYNOPSIS
#include <string.h> size_t strxfrm(char *restrict s1, const char *restrict s2, size_t n); DESCRIPTION
The strxfrm() function shall transform the string pointed to by s2 and place the resulting string into the array pointed to by s1. The transformation is such that if strcmp() is applied to two transformed strings, it shall return a value greater than, equal to, or less than 0, corresponding to the result of strcoll() applied to the same two original strings. No more than n bytes are placed into the resulting array pointed to by s1, including the terminating null byte. If n is 0, s1 is permitted to be a null pointer. If copying takes place between objects that overlap, the behavior is undefined. The strxfrm() function shall not change the setting of errno if successful. Since no return value is reserved to indicate an error, an application wishing to check for error situations should set errno to 0, then call strxfrm(), then check errno. RETURN VALUE
Upon successful completion, strxfrm() shall return the length of the transformed string (not including the terminating null byte). If the value returned is n or more, the contents of the array pointed to by s1 are unspecified. On error, strxfrm() may set errno but no return value is reserved to indicate an error. ERRORS
The strxfrm() function may fail if: EINVAL The string pointed to by the s2 argument contains characters outside the domain of the collating sequence. The following sections are informative. EXAMPLES
None. APPLICATION USAGE
The transformation function is such that two transformed strings can be ordered by strcmp() as appropriate to collating sequence informa- tion in the program's locale (category LC_COLLATE ). The fact that when n is 0 s1 is permitted to be a null pointer is useful to determine the size of the s1 array prior to making the trans- formation. RATIONALE
None. FUTURE DIRECTIONS
None. SEE ALSO
strcmp(), strcoll(), the Base Definitions volume of IEEE Std 1003.1-2001, <string.h> COPYRIGHT
Portions of this text are reprinted and reproduced in electronic form from IEEE Std 1003.1, 2003 Edition, Standard for Information Technol- ogy -- Portable Operating System Interface (POSIX), The Open Group Base Specifications Issue 6, Copyright (C) 2001-2003 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 . IEEE
/The Open Group 2003 STRXFRM(3P)