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Top Forums Shell Programming and Scripting writing the timestamp to as a header in a file Post 302576950 by agama on Sunday 27th of November 2011 04:13:19 PM
Old 11-27-2011
Quote:
Originally Posted by jdsony
if possible could you please explain the command. it works but i don't understand it properly.
The parentheses cause all of the commands to be run in a sub-shell. As such, the standard output from all of the commands goes to the same place so (command1; command2) >file nicely writes all of the output with the header line as you wanted. The && causes the next command on the line to be executed only if the previous command (the sub-shell) executed and returned a good return code. Thus, the move command is run only if the tmp file was successfully created. This prevents overlaying the original file with potentially bad data in the tmp file if the command failed. This is important if the data is difficult to, or cannot be, recreated.

Hope this helps you understand.
 

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GMSTRFTIME(3)								 1							     GMSTRFTIME(3)

gmstrftime - Format a GMT/UTC time/date according to locale settings

SYNOPSIS
string gmstrftime (string $format, [int $timestamp = time()]) DESCRIPTION
Behaves the same as strftime(3) except that the time returned is Greenwich Mean Time (GMT). For example, when run in Eastern Standard Time (GMT -0500), the first line below prints "Dec 31 1998 20:00:00", while the second prints "Jan 01 1999 01:00:00". PARAMETERS
o $format - See description in strftime(3). o $timestamp - The optional $timestamp parameter is an integer Unix timestamp that defaults to the current local time if a $timestamp is not given. In other words, it defaults to the value of time(3). RETURN VALUES
Returns a string formatted according to the given format string using the given $timestamp or the current local time if no timestamp is given. Month and weekday names and other language dependent strings respect the current locale set with setlocale(3). EXAMPLES
Example #1 gmstrftime(3) example <?php setlocale(LC_TIME, 'en_US'); echo strftime("%b %d %Y %H:%M:%S", mktime(20, 0, 0, 12, 31, 98)) . " "; echo gmstrftime("%b %d %Y %H:%M:%S", mktime(20, 0, 0, 12, 31, 98)) . " "; ?> SEE ALSO
strftime(3). PHP Documentation Group GMSTRFTIME(3)
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