Linux: search and replace commands

Linux: search and replace commands

Linux: search and replace commands 150 150 Roderick Derks

Search and replace one file with the same name in several directories
# find . -name "favicon.ico" -exec cp /username/images/favicon.ico {} \;
# find . -name "favicon.ico" -exec ls -al {} \;

Search and replace files with the same name or the same part of the name
# find . -name file.cfg.old -exec rename .cfg.old .cfg {} \;

Find files containing a certain string
# find . -type f -exec egrep -i "search_this_string" /dev/null {} \;

Search .c and .h for "search string" in this dir and below
# find -name "*.[ch]" | xargs grep -E "search string"

Finds all files created in the last day that are larger than 150GB.
# find / -mtime -1 -size +150000000 -print

Search and replace text in several files:
# perl -pi -e "s/search/replace/g;" *.txt

recursively:
# find ./ -exec perl -p -i -e ’s/search/replace/g’ {} \;
# find . -name '*.cfgl' -print0 | xargs -0 perl -pi -e 's/search/replace/g'

Add text from a file to al files in a directory:
for i in `ls -b .`; do cat ../add >> $i; done

Replace a certain string in a file by anther string from the same file using a variable:
for file in $(grep -l "vervang" *); do host_name=$(cat $file|grep host_name|grep -v verv|awk 'BEGIN {FS = "host_name"} {print $2}' |awk '{print $1}'|awk '{print $0}'); echo hostname is $host_name ; sed "s/vervang/${host_name}/g" $file >/tmp/$$ && mv /tmp/$$ $file;donefor file in $(grep -l "##HOSTNAME##" *); do host_name=$(cat $file|grep " host_name"|grep -v HOSTNAME|awk 'BEGIN {FS = "host_name"} {print $2}' |awk '{print $1}'|awk '{print $0}'); echo hostname is $host_name ; sed "s/##HOSTNAME##/${host_name}/g" $file >/tmp/$$ && mv -f /tmp/$$ $file;done

Search files that are:
newer than today 00:00 hr:
touch -t `date +%m%d0000` /tmp/$$| find . -type f -newer /tmp/$$

newer then today 14:00 hr:
touch -t `date +%m%d1400` /tmp/$$| find . -type f -newer /tmp/$$

recently new/updated files
find . -type f -printf "%TY-%Tm-%Td %TT %p\n" | sort | less

Search and remove a piece of text in a file
sed '/replace_this_piece_of_text/{
:loop
N
/till_this_piece_of_text/d
b loop
}' input_file.txt > output_file.txt

Or when using this in a script and using the same file for input and output (-i option for sed):

#! /bin/bash
function remove_it () {
sed -i ‘/Remove from/{
:loop
N
/Remove upto here/d
b loop
}’ $1
}
remove_it $1

Remove all lines starting with a hash

To remove all lines starting with hast sign (#) from a file, try this:
sed /^#/d filename

The above command will remove all lines starting with # from its output. If you want to write the output to another file, use o/p redirection >
sed /^#/d filename > newfile

But, if you want to over write the file with new o/p, use -i option with sed.
sed -i /^#/d filename

Roderick Derks

Liefhebber van fietsen, van het oplossen van IT puzzels, en van het delen van informatie om anderen te helpen.

All stories by:Roderick Derks

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