# 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 stptrime(), 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, Free Software Foundation, Inc.
Copyright © 2019, Arnold David Robbins.

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