Daily used Linux/Unix commands

Command to list latest modified file from parent directory

ls –lRrta

Options:

-l for long listing

-R for recursive

-r for reverse listing

-t for sorting on modified time

-a for listing all including hidden files

Similar command on windows is: dir /N /S

Command to find a file from given path

find -name -print

e.g.

# find /etc -name "1000-gnu.java.security.provider.Gnu" -print

/etc/java/security/security.d/1000-gnu.java.security.provider.Gnu

Command to find a text by searching recursively entire directory contents

find -type f -print | xargs grep "text to search"

e.g.

# find DOWNLOADS/iotop-0.5/ -type f -print | xargs grep "import struct"

DOWNLOADS/iotop-0.5/build/lib/iotop/netlink.py:import struct

DOWNLOADS/iotop-0.5/build/lib/iotop/genetlink.py:import struct

DOWNLOADS/iotop-0.5/build/lib/iotop/data.py:import struct

DOWNLOADS/iotop-0.5/iotop/netlink.py:import struct

DOWNLOADS/iotop-0.5/iotop/genetlink.py:import struct

DOWNLOADS/iotop-0.5/iotop/data.py:import struct

Check directory existence recursively

find -type d -name "directory name to find" -print

e.g.

# find /exported -type d -name "iotop" -print

/exported/DOWNLOADS/iotop-0.5/build/lib/iotop

/exported/DOWNLOADS/iotop-0.5/iotop

 

Difference between grep, egrep and fgrep

gerp Search a Pa tern from current directory.

egrep (grep -E in linux) is extended grep where additional regular expression metacharacters have been added like +, ?, | and ().

fgrep (grep -F in linux) is fixed or fast grep and behaves as grep but does not recognise any regular expression metacharacters as being special.