-
List the files
in current directory sorted by size ? - ls -l | grep ^- |
sort -nr
-
List the hidden
files in current directory ? - ls -a1 | grep "^\."
-
Delete blank
lines in a file ? - cat sample.txt | grep -v ‘^$’ >
new_sample.txt
-
Search for a
sample string in particular files ? - grep “Debug” *.confHere
grep uses the string “Debug” to search in all files with
extension“.conf” under current directory.
-
Display the
last newly appending lines of a file during appendingdata
to the same file by some processes ? - tail –f
Debug.logHere tail shows the newly appended data into
Debug.log by some processes/user.
-
Display the
Disk Usage of file sizes under each directory in
currentDirectory ? - du -k * | sort –nr (or) du –k . | sort
-nr
-
Change to a
directory, which is having very long name ? - cd
CDMA_3X_GEN*Here original directory name is –
“CDMA_3X_GENERATION_DATA”.
-
Display the all
files recursively with path under current directory ? -
find . -depth -print
-
Set the Display
automatically for the current new user ? - export DISPLAY=`eval
‘who am i | cut -d"(" -f2 | cut -d")" -f1′`Here in above
command, see single quote, double quote, grave ascent is
used. Observe carefully.
-
Display the
processes, which are running under yourusername ? - ps –aef
| grep MaheshvjHere, Maheshvj is the username.
-
List some Hot
Keys for bash shell ? - Ctrl+l – Clears the Screen. Ctrl+r
– Does a search in previously given commands in shell.
Ctrl+u - Clears the typing before the hotkey. Ctrl+a –
Places cursor at the beginning of the command at shell.
Ctrl+e – Places cursor at the end of the command at shell.
Ctrl+d – Kills the shell. Ctrl+z – Places the currently
running process into background.
-
Display the
files in the directory by file size ? - ls –ltr | sort –nr
–k 5
-
How to save man
pages to a file ? - man <command> | col –b >
<output-file>Example : man top | col –b > top_help.txt
-
How to know the
date & time for – when script is executed ? - Add the
following script line in shell script.eval echo "Script is
executed at `date`" >> timeinfo.infHere, “timeinfo.inf”
contains date & time details ie., when script is executed
and history related to execution.
-
How do you find
out drive statistics ? - iostat -E
-
Display disk
usage in Kilobytes ? - du -k
-
Display top ten
largest files/directories ? - du -sk * | sort -nr | head
-
How much space
is used for users in kilobytes ? - quot -af
-
How to create
null file ? - cat /dev/null > filename1
-
Access common
commands quicker ? - ps -ef | grep -i $@
-
Display the
page size of memory ? - pagesize -a
-
Display
Ethernet Address arp table ? - arp -a
-
Display the
no.of active established connections to localhost ? -
netstat -a | grep EST
-
Display the
state of interfaces used for TCP/IP traffice ? - netstat -i
-
Display the
parent/child tree of a process ? - ptree <pid> Example:
ptree 1267
-
Show the
working directory of a process ? - pwdx <pid> Example:
pwdx 1267
-
Display the
processes current open files ? - pfiles <pid> Example:
pfiles 1267
-
Display the
inter-process communication facility status ? - ipcs
-
Display the top
most process utilizing most CPU ? - top –b 1
-
Alternative for
top command ? - prstat -a
