I have to calculate the date - 1. I use this shell: #!/bin/sh DataFlusso='date +"%Y%m%d"' DataFlusso='expr $DataFlusso - 1' but if the date is 20040501 return 20040500. Someone can help me? Thanks!!

You can get yesterday's date with: TZ=aaa24 date +%Y%m%d Or if you are using GNU date, you can do: date --date=yesterday

Hi Fdipaolo, I am having the same date problem, I need to find all files with a date greater than or equal to Jan 1, 2004. I do not know how to go back to jan 1, 2004, can anyone help....! please! camin

Thanks!!! I try to use TZ=aaa24 date +%Y%m%d and now works!!!

I have an other question: TZ is the date a local zone. But I have to put the return value of TZ=aaa24 date +%Y%m%d into a variable DataFlusso. But if I make the assignment DataFlusso = $TZ DataFlusso is blank. Why?

Two functions I wrote long ago that play around with dates for systems the do not have the GNU date command. Feel free to modify them and incorporate them into your scripts. ###################### function leapCheck { # ###################### # Comments: This function was written to determine if Feb ends on the 28th or # on the 29th. It was part of the 24 hour review of errors from the 'errpt' # command. It is not being implemented at this time but the function was left # in for future implementation. ####################### for LastDay in $(cal 02 $(date "+%Y") ) do : done export LastDay } # end of the function leapCheck. This function calculates the dates: ######################### function getStartTime { # ######################### # Comments: Function orginally written to allow a search back 24 hours in the # error log. Function is not implemented but is being left in for possible # future implementation. ######################### Month=$(date "+%m") if [[ $(date "+%d") = 1 ]] then if [[ $(date "+%m") = 1 ]] then (( Year=$(date "+%y") - 1 )) Month=12 Day=31 else (( Month=$Month - 1 )) case $Month in 03 | 06 | 09 | 11 ) LastDay=30 ;; 02 ) : ;; * ) LastDay=31 ;; esac Year=$(date "+%y") (( Month=$(date "+%m") - 1 )) Day=$LastDay fi else Year=$(date "+%y") (( Day=$(date "+%d") -1 )) fi StartTime=$Month$Day$(date "+%H%M")$Year } # end of the getStartTime function

Actually camin, your problem is nothing like fdipaolo's, thus it should really start a new thread. fdipaolo wanted simply to get the date from the system and subtract one day from it.  You want to find files based on a given date. Here is a simple solution, but it comes with a slight flaw: touch -t200401010000 /tmp/Jan01 find /mypath -type f -newer /tmp/Jan01 The above will find files newer than the control file that I created named Jan01, and which has a modify date of Jan 01 00:00. The flaw is that the touch command allows me to specify my desired date stamp only to the nearest minute (00:00) and it defaults to 00:00:00. Since the find command is looking for files newer than this, it will not select files that have a date stamp of exactly Jan 01 00:00:00.  It will select files having a date stamp of Jan 01 00:00:01 and higher. The find command will find files that are "newer than" or "not newer than", when what we really need here is "not older than", which would be equivalent to "equal to or newer than". To avoid missing that one-second window, we could instead do this: touch -t200312312359 /tmp/Dec31 find /mydirtree -type f -newer /tmp/Dec31 That solution will select files that are newer than Dec 31 23:59:00 which means that it would also select files in the 23:59:01 to 23:59:59 range.  So instead of missing files in a one-second window, this solution will give us files in a 59-second window that are too old. I am not good at perl, but I do know that this would be an easy task for perl. There may be a straight-forward way to code it, but if not, I know that perl could pull each file's mtime (number of seconds since Jan 1, 1970):   @file_info = stat("myfile");   print $file_info[9],"\n"; The perl script would want to select files having mtime seconds of 1072936800 or greater, which is exactly Jan 01, 2004 00:00:00. Maybe someone will post the perl solution.