I need help to rename multiple files in a directory based on the delimeter.
Sample:
From
R01235-XYZ-TRAIL.PDF
TO
R01234-TRAIL.PDF
and
From
XYZ-C12345-TRAIL.PDF
TO
C12345-TRAIL.PDF
is it possible to delete based on - delimeter?
I am not specifically removing XYZ but rather remove anything before the first - and the middle occurence between two -.. XYZ is just a representation of the characters in that field.
Thanks!
I tried SED, LS, MV, I also tried RENAME but it seems not working for me.
This might work for you:
rename -n 's/XYZ-//' file
This removes XYZ- from the file name.
If this meets your requirements, remove the -n option for the renaming to take place.
On retrospect, perhaps:
rename -n 's/([A-Z][0-9]{5}-).*-/$1/;s/^.*-([A-Z][0-9]{5}-)/$1/' file
With sed:
sed -E 's/^([A-Z][0-9]{5}-).*-|^.*([A-Z][0-9]{5}-.*)/mv & \1\2/' file
Check the results and then:
sed -E 's/^([A-Z][0-9]{5}-).*-|^.*([A-Z][0-9]{5}-.*)/mv & \1\2/' file | sh
Related
I would like to retain a backup file, only if sed altered the original file.
for example:
I have the following file:
# cat test
This is example file
abcd
efgh
process with sed so there is nothing to change:
# sed -i.BAK "s/AAAA/BBBB/" test
The "test" file is not changed because nothing matched. In this case, I would like to avoid the backup file that was created:
# md5sum test*
d3ca57583595576338ad6f9a01276cd5 test
d3ca57583595576338ad6f9a01276cd5 test.BAK
I learned that what I was asking is not possible by "sed" as I suspected by RTFM.
I solved by adding "if [ grep ... ] " on the expression needed to replace.
The "sed" is performed if and only if the expression exists.
Thanks for the people that commented.
I would request some help with a basic shell script that should do the following job.
File a particular word from a given file (file path is always constant)
Backup the file
Delete the specific word or replace the word with ;
Save the file changes
Example
File Name - abc.cfg
Contains the following lines
network;private;Temp;Windows;System32
I've used the following SED command for the operation
sed -i -e "/Temp;/d" abc.cfg
The output is not as expected. The complete line is removed instead of just the word Temp;
Any help would be appreciated. Thank you
sed matches against lines, and /d is the delete directive, which is why you get a deleted line. Instead, use substitution to replace the offending word with nothing:
sed 's/Temp;//g' abc.cfg
The /g modifier means "globlal", in case the offending word appears more than once. I would hold off on the -i (inline) flag until you are sure of your command, in general, or use -i .backup.
Thank you. I used your suggestion but couldn't get through. I appreciate the input though.
I was able to achieve this using the following SED syntax
sed -e "s/Temp//g" -i.backup abc.cfg
I wanted to take the backup before the change & hence -i was helpful.
I'm very very very new to programming and trying to learn how to make tedious analysis tasks a little faster. I have a master folder (Master) with 50 experiment folders and within each experiment folder are another set of folders holding text files. I want to extract 2 lines from one of the text fiels (experiment title on line 7, slope on line 104) and copy them to a new single file.
So far, all I have learned is how to extract the lines and add to a new file.
sed -n '7p; 104 p' reco.txt >> results.txt
How can I extract these two lines from all files 'reco.txt' in the subfolder of the folder 'Master' and export into a single text file?
As much explanation as you can bear would be great to help me learn.
You can use find in combination with xargs for this. On its own, you can get a list of all relevant files:
find . -name reco.txt -print
This finds all files named reco.txt in the current directory (.) or any subdirectories and writes them to standard output.
Now, normally you can use the -exec argument to find, which will run a program for each file found, except that typically multiple results are combined into a single execution (appended to the command line). Your particular invocation of sed only works on one file at a time.
So, instead of -exec, you can use xargs which is essentially the same thing but with more control.
find Master -name reco.txt -print0 | xargs -0 -n1 sed -n '7p; 104 p' > results.txt
This does the following:
Searches in the directory Master or subdirectories for any file named reco.txt.
Outputs each filename with null-terminator instead of newline (-print0) -- this allows the full path to contain characters that usually need escaping (such as spaces)
Pipes the result into xargs, which does the following:
Accepts null-terminated strings (-0)
Only puts at most one file into each command (-n1)
Runs sed -n '7p; 104 p' on that file
Entire output is redirected to results.txt, which will overwrite any existing contents in the file.
I'm trying to do use the sed command in a shell script where I want to remove lines that read STARTremoveThisComment and lines that read removeThisCommentEND.
I'm able to do it when I copy it to a new file using
sed 's/STARTremoveThisComment//' > test
But how do I do this by using the same file as input and output?
sed -i (or the extended version, --in-place) will automate the process normally done with less advanced implementations, that of sending output to temporary file, then renaming that back to the original.
The -i is for in-place editing, and you can also provide a backup suffix for keeping a copy of the original:
sed -i.bak fileToChange
sed --in-place=.bak fileToChange
Both of those will keep the original file in fileToChange.bak.
Keep in mind that in-place editing may not be available in all sed implementations but it is in GNU sed which should be available on all variants of Linux, as per your tags.
If you're using a more primitive implementation, you can use something like:
cp oldfile oldfile.bak && sed 'whatever' oldfile >newfile && mv newfile oldfile
You can use the flag -i for in-place editing and the -e for specifying normal script expression:
sed -i -e 's/pattern_to_search/text_to_replace/' file.txt
To delete lines that match a certain pattern you can use the simpler syntax. Notice the d flag:
sed -i '/pattern_to_search/d' file.txt
You really should not use sed for that. This question seems to come up ridiculously often, and it seems very strange that it does since the general solution is so trivial. It seems bizarre that people want to know how to do it in sed, and in python, and in ruby, etc. If you want to have a filter operate on an input and overwrite it, use the following simple script:
#!/bin/sh -e
in=${1?No input file specified}
mv $in ${bak=.$in.bak}
shift
"$#" < $bak > $in
Put that in your path in an executable file name inline, and then the problem is solved in general. For example:
inline input-file sed -e s/foo/bar/g
Now, if you want to add logic to keep multiple backups, or if you have some options to change the backup naming scheme, or whatever, you fix it in one place. What's the command line option to get 1-up counters on the backup file when processing a file in-place with perl? What about with ruby? Is the option different for gnu-sed? How does awk handle it? The whole friggin' point of unix is that tools do one thing only. Handling logic for backup files is a second thing, and needs to be factored out. If you are implementing a tool, do not add logic to create backup files. Tell your users to use a 2nd tool for that. Integration is bad. Modularity is good. That is the unix way.
Notice that this script has several problems. The permissions/mode of the input file may be changed, for example. I'm sure there are innumerable other issues. However, by putting the backup logic in a wrapper script, you localize all of these issues and don't have to worry that sed overwrites the files and changes mode, while python keeps the file in place and does not change the inode (I made up those two cases, the point being that not all tools will use the same logic, while the wrapper script will.)
As far as I know it is not possible to use the same file for input and output. Though one solution is make a shell script which will save it to another file, delete the old input and rename the output to the input file name.
sed -e s/try/this/g input.file > output.file;mv output.file input.file
I suggest using sponge
sponge reads standard input and writes it out to the specified file.
Unlike a shell redirect, sponge soaks up all its input before writing
the output file. This allows constructing pipelines that read from and
write to the same file.
cat test | sed 's/STARTremoveThisComment//' | sponge test
I am back with a second no-brainer question, but I would like to get this straight in my head.
I have an assignment in which I am charged with providing a command to find a file named test in my home directory (one command using find, and one using grep). I understand that using find is just 'find ~/test', but using grep, wouldn't I have to search out a pattern within the file 'test'? Or is there a way to search for the file (using grep), even if the file is empty?
ls ~ | grep test
I understand that using find is just 'find ~/test'
No. find ~/test will also have a match for every file or directory under the directory $HOME/test/. Rather use find ~ -type f -name test.
The assignment sounds unclear. But yes, if you give any filenames to grep, it will look at the contents of the files and ignore the names of the files. Perhaps you can grep the output of another command? Maybe ls as #Reese suggested, or maybe a different find command.
ls -R ~ | grep test
Explanation: ls -R ~ will recursively list all files and directories in your home folder. grep test will narrow down that list to files (and directories) that have "test" in their name.