View source for Using sed head tail and cat on large text files


 sed -n -e Xp -e Yp FILENAME

    sed : sed command, which will print all the lines by default.
    -n : Suppresses output.
    -e CMD : Command to be executed
    Xp: Print line number X
    Yp: Print line number Y
    FILENAME : name of the file to be processed.

 sed -n -e 120p -e 145p -e 1050p /var/log/syslog

 sed -n M,Np FILENAME

 sed -n 101,110p /var/log/cron

displays only first 15 lines of /var/log/maillog file.
 head -n 15 /var/log/maillog

display all the lines of the /var/log/secure except the last 250 lines.
 head -n -250 /var/log/secure

 tail -n 50 /var/log/messages

ignores the 1st four lines of the /etc/xinetd.conf, which contains only the comments.

 tail -n +5 /etc/xinetd.conf

follow live

 tail -f /var/log/syslog

display line numbers 101 – 110 of /var/log/anaconda.log file

 cat /var/log/anaconda.log | tail -n +101 | head -n 10

See the following web site for details on these examples:

reference: http://www.thegeekstuff.com/2009/08/10-awesome-examples-for-viewing-huge-log-files-in-unix/


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[[Category:Computer_Technology]]
[[Category:Linux]]