Man Pages

ctime(3p) - phpMan ctime(3p) - phpMan

Command: man perldoc info search(apropos)  


CTIME(3P)                  POSIX Programmer's Manual                 CTIME(3P)



PROLOG
       This manual page is part of the POSIX Programmer's Manual.  The Linux implementation of this interface may dif-
       fer (consult the corresponding Linux manual page for details of Linux behavior), or the interface  may  not  be
       implemented on Linux.

NAME
       ctime, ctime_r - convert a time value to a date and time string

SYNOPSIS
       #include <time.h>

       char *ctime(const time_t *clock);


       char *ctime_r(const time_t *clock, char *buf);


DESCRIPTION
       For  ctime():   The functionality described on this reference page is aligned with the ISO C standard. Any con-
       flict between the requirements described  here  and  the  ISO C  standard  is  unintentional.  This  volume  of
       IEEE Std 1003.1-2001 defers to the ISO C standard.

       The  ctime() function shall convert the time pointed to by clock, representing time in seconds since the Epoch,
       to local time in the form of a string. It shall be equivalent to:


              asctime(localtime(clock))

       The asctime(), ctime(), gmtime(), and localtime() functions shall return values in one of two static objects: a
       broken-down  time  structure and an array of char. Execution of any of the functions may overwrite the informa-
       tion returned in either of these objects by any of the other functions.

       The ctime() function need not be reentrant. A function that is not required to be reentrant is not required  to
       be thread-safe.

       The  ctime_r()  function  shall convert the calendar time pointed to by clock to local time in exactly the same
       form as ctime() and put the string into the array pointed to by buf (which shall be at least 26 bytes in  size)
       and return buf.

       Unlike ctime(), the thread-safe version ctime_r() is not required to set tzname.

RETURN VALUE
       The  ctime() function shall return the pointer returned by asctime() with that broken-down time as an argument.

       Upon successful completion, ctime_r() shall return a pointer to the string pointed to by buf. When an error  is
       encountered, a null pointer shall be returned.

ERRORS
       No errors are defined.

       The following sections are informative.

EXAMPLES
       None.

APPLICATION USAGE
       Values for the broken-down time structure can be obtained by calling gmtime() or localtime(). The ctime() func-
       tion is included for compatibility with older implementations, and does not support  localized  date  and  time
       formats.  Applications should use the strftime() function to achieve maximum portability.

       The  ctime_r()  function  is  thread-safe and shall return values in a user-supplied buffer instead of possibly
       using a static data area that may be overwritten by each call.

RATIONALE
       None.

FUTURE DIRECTIONS
       None.

SEE ALSO
       asctime(), clock(), difftime(), gmtime(), localtime(), mktime(), strftime(), strptime(), time(),  utime(),  the
       Base Definitions volume of IEEE Std 1003.1-2001, <time.h>

COPYRIGHT
       Portions of this text are reprinted and reproduced in electronic form from IEEE Std 1003.1, 2003 Edition, Stan-
       dard for Information Technology -- Portable Operating System Interface (POSIX), The Open Group Base  Specifica-
       tions  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 Stan-
       dard,  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                            CTIME(3P)