mtime, ctime, and atime Post: 302134305

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Top Forums UNIX for Beginners Questions & Answers Answers to Frequently Asked Questions Tips and Tutorials mtime, ctime, and atime Post 302134305 by Perderabo on Thursday 30th of August 2007 09:13:22 AM

08-30-2007

Administrator Emeritus

Using perl to display the file timestamps

The ls program will display mtime if you use "ls -l". And you can get atime or ctime with "ls -lu" or "ls -lc". But ls uses a strange format. It displays the month and day in all cases. If the timestamp is recent, it also displays hour and minute. If the timestamp is older than 6 months, it display the year instead of hour and minute. A clever script can reformat this to year, month, day, hour, and minute. But ls will not display the seconds. The gnu version of ls (which is usually the only version on linux) does have extended options like --fulltime. But these extended options are non-standard and won't be available on other versions of Unix.

The perl language is also non-standard, but perl tends to be available on most versions of unix. For example, a version of perl is supplied with HP-UX and Solaris. Perl can easily display the timestamps of files. Here are some perl one-liners to display atime, mtime, and ctime.

Code:

$ echo hello > testfile ; date
Thu Aug 30 08:31:57 EDT 2007
$ chmod 700 testfile ; date
Thu Aug 30 08:32:48 EDT 2007
$ cat testfile ; date
hello
Thu Aug 30 08:33:30 EDT 2007
$
$
$
$
$ perl -e '@d=localtime ((stat(shift))[8]); printf "%4d%02d%02d%02d%02d%02d\n", $d[5]+1900,$d[4]+1,$d[3],$d[2],$d[1],$d[0]' testfile
20070830083330
$ perl -e '@d=localtime ((stat(shift))[9]); printf "%4d%02d%02d%02d%02d%02d\n", $d[5]+1900,$d[4]+1,$d[3],$d[2],$d[1],$d[0]' testfile
20070830083157
$ perl -e '@d=localtime ((stat(shift))[10]); printf "%4d%02d%02d%02d%02d%02d\n", $d[5]+1900,$d[4]+1,$d[3],$d[2],$d[1],$d[0]' testfile
20070830083248
$

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LEARN ABOUT MINIX

date

DATE(1) 						      General Commands Manual							   DATE(1)

NAME

       date - print or set the date and time

SYNOPSIS

       date [-qsu] [[MMDDYY]hhmm[ss]] [+format]

OPTIONS

       -q     Read the date from stdin

       -s     Set the time (implicit for -q or a date string)

       -u     Print the date as GMT

       -t     Use this number of seconds instead of current time

EXAMPLES

       date		   # Print the date and time

       date 0221921610	   # Set date to Feb 21, 1992 at 4:10 p.m.

DESCRIPTION

       With  the  -q flag or a numeric argument, date sets the GMT time and date.  MMDDYY refers to the month, day, and year; hhmmss refers to the
       hour, minute and second.  Each of the six fields must be exactly two digits, no more and no less.  date always display the date	and  time,
       with  the  default format for the system.  The -u flag request GMT time instead of local time.  A format may be specified with a + followed
       by a printf-like string with the following options:

	 %%  % character
	 %A  Name of the day
	 %B  Name of the month
	 %D  mm/dd/yy
	 %H  Decimal hour on 2 digits
	 %I  Decimal hour modulo 12 on 2 digits
	 %M  Decimal minute on 2 digits
	 %S  Decimal seconds on 2 digits
	 %T  HH:MM:SS
	 %U  Decimal week number, Sunday being first day of week
	 %W  Decimal week number, Monday being first day of week
	 %X  Same as %T
	 %Y  Decimal year on 4 digits
	 %Z  Time Zone (if any)
	 %a  Abbreviated name of the day
	 %b  Abbreviated name of the month
	 %c  Appropriate date & time (default format)
	 %d  Decimal day of the month on 2 digits
	 %e  Same as %d, but a space replaces leading 0
	 %h  Same as %b
	 %j  Decimal dey of the year on 3 digits
	 %m  Decimal month on 2 digits
	 %n  Newline character
	 %p  AM or PM
	 %r  12-hour clock time with AM/PM
	 %s  Number of seconds since the epoch
	 %t  Tab character
	 %w  Decimal day of the week (0=Sunday)
	 %x  Same as %D
	 %y  Decimal year on 2 digits

SEE ALSO

       time(2), ctime(3), readclock(8).

																	   DATE(1)