What are the best search and replace tools in linux?
I want to find an easy way.
Thanks
You can use rpl.
It will replace strings with new strings in multiple text files. It can work recursively over directories and supports limiting the search to specific file suffixes.
rpl [-iwRspfdtx [-q|-v]] <old_str> <new_str> <target_file(s)>
find for finding files/directories
grep or ack[1] for searching files
sed for search/replace in files
awk and cut for slicing/dicing text
for anything non-trivial I usually reach for perl
[1] http://betterthangrep.com/
find and sed are the classic tools.
Related
Using standard Unix tools how can I search in a text file or output for a word with maybe 1-2 letters transposed or missed?
For example my input
function addtion(number, increment)
return number+increment
end
function additoin(number, increment)
return number+increment
end
I would like to search for addition and match addtion and additoin in my input and tell me about it. Because it's code, checking against dictionary is out of the question.
Currently cat file.txt | grep "addition" will simply yield me nothing.
You can play around with the agrep command. It can perform fuzzy, approximate matches.
The following command worked for me:
agrep -2 addition file
You can't do a fuzzy match with standard grep, but if there are specific misspelling you're interested in, you could construct a regular expression that matches those.
For example:
grep add[it]*on
matches the example misspelling you gave. But that's probably not general enough for your purposes.
A better approach is likely going to be to use some sort of static analysis tool specific to the language the code is in. It might not give you the right spelling, but should be able to tell you where the function name and calls to the function use different spellings.
Try the spell command. Note: You might need a dictionary (usually aspell-en in your distro's repositories).
As the answer says, you should definitely try agrep. In addition, there is a newer and much faster alternative ugrep for fuzzy search. Use -Z2 to allow up to 2 errors:
ugrep -Z2 addition file.txt
An insertion, deletion, or substitution is one error. A transposition (as in additoin) counts as two errors, i.e. two substitutions. Use option -i for case-insensitive search and -w to match whole words.
Try this on linux terminal:
grep -rnw "text" ./
I know how to match text using regex patterns but not how to manipulate them.
I have used grep to match and extract lines from a text file, but I want to remove those lines from the text. How can I achieve this without having to write a python or bash shell script?
I have searched on Google and was recommended to use sed, but I am new to it and don't know how it works.
Can anyone point me in the right direction or help me achieve this goal?
The -v option to grep inverts the search, reporting only the lines that don't match the pattern.
Since you know how to use grep to find the lines to be deleted, using grep -v and the same pattern will give you all the lines to be kept. You can write that to a temporary file and then copy or move the temporary file over the original.
grep -v pattern original.file > tmp.file
mv tmp.file original.file
You can also use sed, as shown in shellfish's answer.
There are multiple possible refinements for the grep solution, but for most people most of the time, what is shown is more or less adequate (it would be a good idea to use a per process intermediate file name, preferably with a random name such as the mktemp command gives you). You can add code to remove the intermediate file on an interrupt; suppress interrupts while moving back; use copy and remove instead of move if the original file has multiple hard links or is a symlink; etc. The sed command more or less works around these issues for you, but it is not cognizant of multiple hard links or symlinks.
Create the pattern which matches the lines using grep. Then create a sed script as follows:
sed -i '/pattern/d' file
Explanation:
The -i option means overwrite the input file, thus removing the files matching pattern.
pattern is the pattern you created for grep, e.g. ^a*b\+.
d this sed command stands for delete, it will delete lines matching the pattern.
file this is the input file, it can consist of a relative or absolute path.
For more information see man sed.
I was asked today to list all image files references in our project to help remove/fix dead references.
All our image names in the source files are enclosed in either simple or double quotes ('image.png' or "image.png").
To extract those I thought of using grep, sed an other tools like that but so fair I failed to come up with something effective.
I can currently list all lines that contain image names by grepping the image file extensions (.png, .gif, and so on) but that also brings lines completely unrelated to my search. My attempt with sed wasn't working in case there was several strings per line.
I could probably filter out the list by myself, but hey: this is linux ! So there has to be a tool for the job.
How would you do that ?
You should be able to extract the file names with something like this:
grep -Eo "['\"][^'\"]*\.(gif|png)['\"]"
The option -o causes grep to list only the matches instead of the whole line. Use tr to remove the quotes:
grep -Eo "['\"][^'\"]*\.(gif|png)['\"]" | tr -d "\"'"
i have hundreds of files with special characters ('æ', 'ø' and 'å') in their filenames.
i cannot copy these to my external mntfs disk without renaming.
the files are in dozens of different folders. there are thousands of other files without these letters in there as well.
i'd like to replace the special characters with their placeholders ('ae', 'oe' and 'aa'), while keeping the rest of the filename intact.
i'm on ubuntu. i'm thinking of using grep, sed and tr, but i don't know exactly how.
You can use rename command from util-linux package.
For example,
find / -type f -exec rename 'â' 'a' {} \;
convmv is used to convert filenames between encodings. I'm sure it can solve your problem, even if it might not be exactly what you asked for.
I need to do things like: taking the first x lines of text file and save it into another text file, what kind of text utilities can I use in windows?
Use a decent text editor like Notepad++ or Vim.
If you aren't afraid of using the command line, I'd suggest taking a look at Gnuwin32, which is a port of many useful *nix utilities for Windows.
It contains heavyweight such as Sed, Awk, Grep etc., which are more than suited for any kind of text surgery.
if you want to write a batchfiles that extracts the first 10 lines of file myInputFile.txt to myOutputFile.txt use
head.exe --lines=10 myInputFile.txt > myOutputFile.txt
head.exe is one of severeal GnuUtilities for MsWindows.