I have a file containing more than 14000 records.
What I want to do is to process this file line by line and replace a String by anodher string returned by grep command.
For example:
Line :
/xxxxx/xxxxx/Class.java:67: Logger.w(TAG, "message");
My grep command to get Class.java string is (Class.java is juste an example):
grep -o '[a-zA-Z]*"*\.java"*'
I must, for each line, replace the TAG string by the class.java string return by grep command
You can use sed and do the following:
sed -r 's#(.*)/(.*)\.java(.*)(TAG)#\1\/\2\3\2#g'
Characters surrounded with parenthesis are groups that you can use in the second part to get their content.
In order to modify the file in-place, you should:
sed -ir 's#(.*)/(.*)\.java(.*)(TAG)#\1\/\2\3\2#g' your_file.txt
This is where sed comes in:
sed -i 's/TAG/class.java/g' Class.java
do it for all java files in current directory (assuming bash here):
sed -i 's/TAG/class.java/g' *.java
-i means in-place, so replacing takes place inside the file and is saved immediately. For the rest I suggest you google about sed.
You can use:
grep -rl 'old_string' ./ | xargs sed -i 's/old_string/Relacement_String/g'
Related
I am trying to replace string into number from the file
So, I have variable &FLOW which need to change to 001, ex :
cat file.txt
This is file ' PISP &FLOW'
PISD.DATA.CYCLE&FLOW..ONE
desired output
This is file ' PISP 001'
PISD.DATA.CYCLE001.ONE
I tried below commands in a script :
for item in file.txt
do
sed 's/\&FLOW/\./001/g' $item
sed 's/\&FLOW/001/g' $item
done
It is giving error. The second sed command is working, but I need to run first the beginning sed command otherwise after running first the second sed command, it would ignore the beginning sed command.
Any help would be appreciated!
Use a single sed command and use -i to actually modify the file contents and you need to pass file.txt as the input for the sed command:
sed -i 's/&FLOW\.\{0,1\}/001/g' file.txt
See the online demo. If you are using it in Mac OS, you need sed -i '' 's/&FLOW\.\{0,1\}/001/g' file.txt. Also see sed edit file in place.
Pattern details
It is a POSIX BRE compliant pattern matching
&FLOW - a literal &FLOW substring
\.\{0,1\} - 0 or 1 occurrence of a . char.
try this:
for item in file.txt
do
sed 's/\&FLOW\./001/g' $item
sed 's/\&FLOW/001/g' $item
done
You had a redundant / in after FLOW
This might also work:
sed -i 's/\&FLOW[\.]?/001/g' file.txt
I need to replace first 4 header lines of only selected 250 erlang files (with extension .erl), but there are 400 erlang files in total in the directory+subdirectories, I need to avoid modifying the files which doesn't need the change.
I've the list of file names that are to be modified, but don't know how to make my linux command to make use of them.
sed -i '1s#.*#%% This Source Code Form is subject to the terms of the Mozilla Public#' *.erl
sed -i '2s#.*#%% License, v. 2.0. If a copy of the MPL was not distributed with this file,#' *.erl
sed -i '3s#.*#%% You can obtain one at http://mozilla.org/MPL/2.0/.#' *.erl
sed -i '4s#.*##' *.erl
in the above commands instead of passing *.erl I want to pass those list of file names which I need to modify, doing that one by one will take me more than 3 days to complete it.
Is there any way to do this?
Iterate over the shortlisted file names using awk and use xargs to execute the sed. You can execute multiple sed commands to a file using -e option.
awk '{print $1}' your_shortlisted_file_lists | xargs sed -i -e first_sed -e second_sed $1
xargs gets the file name from awk in a $1 variable.
Try this:
< file_list.txt xargs -1 sed -i -e 'first_cmd' -e 'second_cmd' ...
Not answering your question but a suggestion for improvement. Four sed commands for replacing header is inefficient. I would instead write the new header into a file and do the following
sed -i -e '1,3d' -e '4{r header' -e 'd}' file
will replace the first four lines of the file with header.
Another concern with your current s### approach is you have to watch for special chars \, & and your delimiter # in the text you are replacing.
You can apply the sed c (for change) command to each file of your list :
while read file; do
sed -i '1,4 c\
%% This Source Code Form is subject to the terms of the Mozilla Public\
%% License, v. 2.0. If a copy of the MPL was not distributed with this file,\
%% You can obtain one at http://mozilla.org/MPL/2.0/.\
' "$file"
done < filelist
Let's say you have a file called file_list.txt with all file names as content:
file1.txt
file2.txt
file3.txt
file4.txt
You can simply read all lines into a variable (here: files) and then iterate through each one:
files=`cat file_list.txt`
for file in $files; do
echo "do something with $file"
done
Say for instance I'm searching a line that is like this:
Color asdf
and I use grep to find that line, like grep asdf file.txt
How would I then display Color? Learning linux is hard.
With the command line tool sed you can replace stings by using regular expressions:
echo "Color asdf" | sed 's/\([^ ]*\).*/\1/'
This part: \([^ ]*\).* is a regular expresion. The first part of the regex: [^ ]*, matches any character except a space as many times as possible and what's between the \( and \) is being captured in the variable \1. Then you also match the remaining part of the string with .* and replace all of that with only the first word which was captured by \([^ ]*\) by using \1 in the replace part of the sed command.
Here some more info about sed:
http://linux.about.com/od/commands/a/Example-Uses-Of-Sed-Cmdsedxa.htm
You could use sed:
sed -n 's/[[:space:]][[:space:]]*asdf$//p' file.txt
Details:
The -n option tells sed not to print the pattern space automatically. Basically, it doesn't output anything unless you tell it to.
The s command of sed replaces text. Here, if a line ends with asdf, preceded by at least one whitespace character, we replace all of that with nothing and then print the line (notice the p flag at the end of the s command). The printing is only done if something was actually replaced. More information about the s command can be found e. g. in the GNU sed manual.
Edit for clarity: When using single quotes, parameter expansion does not work and thus, variables won't be replaced. To use variables, use double quotes:
search=asdf
sed -n "s/[[:space:]][[:space:]]*${search}\$//p" file.txt
If you'd really like to use grep here, you could pipe the output from grep into cut:
grep -h asdf *.txt | cut -s -d -f 1
Note that there have to be two spaces after the -d option to cut - the first tells cut to use a blank as the field delimiter (I'm assuming your fields are blank-delimited rather than tab-delimited), while the second separates the -d option from the following option (-f).
But, yeah, sed or awk are probably your friends here... :-)
you can color pattern in the line using grep
grep --colour -o 'asdf' file.txt
edit: the -o option will print only the patterns
I need to replace a string / line for each instance of that string / line.
In the following line:
set output "/DS/tmp/2.gnuplot.ps"
I need it to be:
set output "./gnuplot.ps"
I want to use:
grep -rl 'stringONE' ./ | xargs sed -i 's/stringONE/stringTWO/g'
but when I try to use it, it has a conflict with the / in the string...
grep -rl '/DS/tmp/2.gnuplot.ps' ./ | xargs sed -i 's//DS/tmp/2.gnuplot.ps/./gnuplot.ps/g'
Any help will be greatly appreciated!!!
If the string to be replaced contains slash (/) then you can delimit arguments of sed's s command with something else, in this case I used comma:
grep -rl '/DS/tmp/2.gnuplot.ps' ./|xargs sed -i 's,/DS/tmp/2.gnuplot.ps,./gnuplot.ps,g'
I have a text file with a bunch of file paths such as -
web/index.erb
web/contact.erb
...
etc. I need to append before the
</head>
a line of code, to every single file, I'm trying to figure out how to do this without opening each file of course. I've heard sed, but I've never used it before..was hoping there would be a grep command maybe?
Thanks
xargs can be used to apply sed (or any other command) to each filename or argument in a list. So combining that with Rom1's answer gives:
xargs sed -i 's/<\/html>/myline\n<\/html>/g' < fileslist.txt
while read f ; do
sed -i '/<\/head>/i*iamthelineofcode*' "$f"
done <iamthefileoffiles.list
or
sed -i '/<\/head>/i*iamthelineofcode*' $(cat iamthefileoffiles.list)