-------------------AWK--------------------
1) Pattern scanning and text processing language
awk one-liner Tips
Print column1, column5 and column7 of a data file or output of any columns list
$awk ‘{print $1, $5, $7}’ data_file
$cat file_name |awk ‘{print $1 $5 $7}’
$ls –al |awk ‘{print $1, $5, $7}’ -- Prints file_permissions,size and date
Syntax of running an awk program
Awk ‘program’ input file(s)
List all files names whose file size greater than zero.
$ls –al |awk ‘$5 > 0 {print $9}’
List all files whose file size equal to 512bytes.
$ls –al |awk ‘$5 == 0 {print $9}’
print all lines
$awk ‘{print }’ file_name
$awk ‘{print 0}’ file_name
Number of lines in a file
$awk ‘ END {print NR}’ file_name
Number of columns in each row of a file
$awk ‘ {print NF’} file_name
Sort the output of file and eliminate duplicate rows
$awk ‘{print $1, $5, $7}’ |sort –u
List all file names whose file size is greater than 512bytes and owner is "oracle"
$ls –al |awk ‘$3 == "oracle" && $5 > 512 {print $9}’
List all file names whose owner could be either "oracle" or "root"
$ls –al |awk ‘$3 == "oracle" || $3 == "root" {print $9}’
list all the files whose owner is not "oracle
$ls –al |awk ‘$3 != "oracle" {print $9}’
List all lines which has atlease one or more characters
$awk ‘NF > 0 {print }’ file_name
List all lines longer that 50 characters
$awk ‘length($0) > 50 ‘{print }’ file_name
List first two columns
$awk ‘{print $1, $2}’ file_name
Swap first two columns of a file and print
$awk ‘{temp = $1; $1 = $2; $2 = temp; print }’ file_name
Replace first column as "ORACLE" in a data file
$awk ‘{$1 = "ORACLE"; print }’ data_file
Remove first column values in a data file
$awk ‘{$1 =""; print }’ data_file
Calculate total size of a directory in Mb
$ls –al |awk ‘{total +=$5};END {print "Total size: " total/1024/1024 " Mb"}’
Calculate total size of a directory including sub directories in Mb
$ls –lR |awk ‘{total +=$5};END {print "Total size: " total/1024/1024 " Mb"}’
Find largest file in a directory including sub directories
$ls –lR |awk ‘{print $5 "\t" $9}’ |sort –n |tail -1
$ awk -F":" '{ print $1 $3 }' /etc/passwd
$ awk -f myscript.awk myfile.in
------------------SED---------------------
1) Stream editor for filtering and transforming text
2) Sed works as filter, which makes it particularly useful for scripts, sed works line oriented. The most simple commands are a pattern and an action . if no pattern is given, then action is applied to all lines, otherwise it is applied only to lines matching the pattern.
EXAMPLE::
1) A sample application of sed would be to delete the first 10 lines of stdin and echo the rest to stdout:
$cat /etc/passwd| sed -e '1,10d'
2) If we wanted to print only the first ten lines, we would have deleted all the lines starting with 11:
$cat /etc/passwd| sed -e '11,$d'
3)Another way to get only the first 10 lines is to use the -n option:
$cat /etc/passwd | sed -n -e '1,10p'
4)Commands in sed programs are separated by new lines. So if we wanted to delete the lines 1 to 4 and 6 to 9, we could use:
$cat /etc/passwd | sed -e '1,4d
6,9d'
5)If we want to put command in the script files instead of using the command line.
$sed -f program.sed
