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In the following command, how can I get the file names based on its timestamp 

$ grep "exit 0" a*
a1.txt:+ exit 0
a2.txt:+ exit 0
a3.txt:+ exit 0
a4.txt:+ exit 0
a5.txt:+ exit 0

$ ls -latr 
-rw-r--r-- 1 user grp  83046 Oct 27 06:46 a5.txt
-rw-r--r-- 1 user grp  68108 Oct 27 07:59 a1.txt
-rw-r--r-- 1 user grp 159792 Oct 27 12:35 a2.txt
-rw-r--r-- 1 user grp 225703 Oct 27 16:41 a3.txt
-rw-r--r-- 1 user grp 246782 Oct 27 20:17 a4.txt

As you see the above output, I am not getting the output based on the timestamp the file was created. Is there any way to achieve it?

jimmij
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janani
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3 Answers3

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If none of the file names contain space, tab, newline (and $IFS has not been modified), ?, *, [ characters or are called -, this should do it:

grep -- "exit 0" $(ls -tr a*)

$() is called command substitution. Your shell will first run ls -tr, then split+glob its output to make up the list of files passed to your grep command.

Stéphane Chazelas
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Omnipresence
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  • Omni, I noticed that your command also displays the output from unmatched files also. For eg. I am trying to grep on a*.txt, but it gives the output on b*txt too. why is it so? – janani Oct 28 '14 at 20:44
  • Sorry it was my bad. Instead of doing, grep "exit 0" $(ls -tr a*), i was doing - grep "exit 0" a* $(ls -tr) – janani Oct 28 '14 at 20:49
  • @Gilles, `--` doesn't protect against a file called `-`. – Stéphane Chazelas Oct 29 '14 at 07:30
  • @janani I'm glad you caught that. I'd meant to include a* in my command to match your example. I'll update the answer for future generations. – Omnipresence Oct 29 '14 at 12:51
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With the zsh shell, you can affect the order of globs with glob qualifiers.

grep 'exit 0' a*(.Om)

Om is to reverse o⃞rder by m⃞odification time. I also added .⃞ to select only regular files (not directories or pipes or devices or symlinks...).

Stéphane Chazelas
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Thanks Omni. Even the following way, I am able to achieve this. Of course urs is the simple one. thanks a lot

       grep -H "exit 0" /opt/ctmagent/ctm/sysout_archives/141027/d_dms_btch_alrt_ifm_scp_ksh* | awk -F":" '{system("ls -latr "$1"")}'
janani
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    That runs one `ls` per file, so is not going to do anything wrt sorting. That also interprets the file name as shell code so is very dangerous. – Stéphane Chazelas Oct 28 '14 at 20:47