NAME

time - time functions for gawk

SYNOPSIS

@load "time"

time = gettimeofday()
ret = sleep(amount)
timeval = strptime(string, format)

DESCRIPTION

The time extension adds three functions named gettimeofday() sleep(), and strptime(), as follows.

gettimeofday()

This function returns the number of seconds since the Epoch as a floating-point value. It should have subsecond precision. It returns -1 upon error and sets ERRNO to indicate the problem.

sleep(seconds)

This function attempts to sleep for the given amount of seconds, which may include a fractional portion. If seconds is negative, or the attempt to sleep fails, then it returns -1 and sets ERRNO. Otherwise, the function should return 0 after sleeping for the indicated amount of time.

strptime()

This function takes two arguments, a string representing a date and time, and a format string describing the data in the string. It calls the C library strptime(3) function with the given values. If the parsing succeeds, the results are passed to the C library mktime(3) function, and its result is returned, expressing the time in seconds since the epoch in the current local timezone, regardless of any timezone specified in the string arguments. (This is the same as gawk's built-in systime() function.) Otherwise it returns -1 upon error. In the latter case, ERRNO indicates the problem.

BUGS

The underlying strptime(3) C library routine apparently ignores any time zone indication in the date string, producing values relative to the current time zone. It might be better to have this routine return a string similar to what gawk's mktime() function expects, but we ran out of energy.

EXAMPLE

@load "time"
...
printf "It is now %g seconds since the Epoch\n", gettimeofday()
...
printf "Pausing for a while... " ; sleep(2.5) ; print "done"
...
format = "%b %d %H:%M:%S %Z %Y"
now = systime()
print now, "<" (result = strftime(format, now)) ">",
then = strptime(result, format)
print strftime(format, then)

SEE ALSO

GAWK: Effective AWK Programming, filefuncs(3am), fnmatch(3am), fork(3am), inplace(3am), ordchr(3am), readdir(3am), readfile(3am), revoutput(3am), rwarray(3am).

gettimeofday(2), nanosleep(2), select(2), and strptime(3).

AUTHOR

Arnold Robbins, arnold@skeeve.com.

COPYING PERMISSIONS

Copyright © 2012, 2013, 2018, 2022, 2023, 2024, Free Software Foundation, Inc.
Copyright © 2019, Arnold David Robbins.

Permission is granted to make and distribute verbatim copies of this manual page provided the copyright notice and this permission notice are preserved on all copies.

Permission is granted to copy and distribute modified versions of this manual page under the conditions for verbatim copying, provided that the entire resulting derived work is distributed under the terms of a permission notice identical to this one.

Permission is granted to copy and distribute translations of this manual page into another language, under the above conditions for modified versions, except that this permission notice may be stated in a translation approved by the Foundation.