I need to find all instances of "[0]" and "[1]" in several files ending in .cpp. The files are located in different sub directories.
Is it poissible to use sed to scan through all .cpp files in sub directories and look for a pattern?
Thanks!
Leave sed alone, it's for stream editing, not searching. Use grep.
find . -iname '*.cpp' | while read filename; do grep --with-filename '\[[01]\]' "$filename"; done
Or in a script:
find . -iname '*.cpp' | while read filename
do
grep --with-filename '\[[01]\]' "$filename"
done
I'm using read here (and quotes around $filename) so that filenames with spaces in survive; in Windows systems this is a particular nightmare.
If you know none of your files are particularly big, you can sacrifice efficiency of search for efficiency of typing and search all the files but only pick out the output from cpp files:
grep -r '\[[01]\]' . | grep '.cpp:'
Related
I have a file named "performance". I need to know which scripts use this file.
I don't believe there is a straight forward way of listing files used by scripts. You will have to run grep in combination of find to check if the script contains the name of the file that you want to check for. Knowing the exact name of the file will help. Using words like performance might end up grepping files that uses that word in comments.
find /path/ \( -name "*.sh" -o -name "*.pl" \) -type f -print0 | xargs -0 grep "performance"
If you're on linux, then you may install and configure auditd to watch for accesses to a particular file.
You can use the -r option to recursively grep through all sub-directories and find text. The syntax is as follows:
grep -r "performance" /dir/
I recently lost a bunch of files from eclipse in an accidental copy/replace dilema. I was able to recover most of them but I found in the eclipse metadata folder a history of files, some of which are the ones I need. The path for the history is:
($WORKSPACE/.metadata/.plugins/org.eclipse.core.resources/.history).
Inside there are a bunch of folders like 3e,2f,1a,ff, etc.. each with a couple files named like "2054f7f9a0d30012175be7013ca49f5b". I was able to do a recursive grep with a keyword i know would be in the file and return a list of file names (grep -R -l 'KEYWORD') and now I can't figure out how to sort them by most recently modified.
any help would be great, thanks!
you can try:
find $WORK.../.history -type f -printf '%T#\t%p\n' | sort -nr | cut -f2- | xargs grep 'your_pattern'
Decomposed:
the find finds all plain files and prints their modification time and path
the sort sort sort them numerically - and reverse, so highest number comes first (the latest modified)
the cut removes the time from each line
the xargs run its argument for each file what get to it input,
in this case will run the grep command, so
the 1st file what the grep find - was the lastest modified
The above not works when the filenames containing spaces, but hopefully this is not your case... The -printf works only with GNU find.
For the repetative work, you can split the command to two parts:
find $WORK.../.history -type f -printf '%T#\t%p\n' | sort -nr | cut -f2- > /somewhere/FILENAMES_SORTED_BY_MODIF_TIME
so in 1st step you save to somewhere the list of filenames sorted by their modification times, and after you can repeatedly use the grep command on their content with:
< /somewhere/FILENAMES_SORTED_BY_MODIF_TIME xargs grep 'your_pattern'
the above command is usually written as
xargs grep 'your_pattern' < /somewhere/FILENAMES_SORTED_BY_MODIF_TIME
but for the bash is OK write the redirection to the start and in this case is simpler changing the pattern for the grep if the pattern is in the last place...
If you want check the list of filenames with modification times, you can break the above commands as:
find $WORK.../.history -type f -printf "%T#\t%Tc\t%p\n" | sort -nr >/somewehre/FILENAMES_WITH_DATE
check the list (they now contains readable date too) and use the next
< /somewehre/FILENAMES_WITH_DATE cut -f3- | xargs grep 'your_pattern'
note, now need to use -f3- and not -f2- as in the 1st example.
I'm trying to change the name of "my-silly-home-page-name.html" to "index.html" in all documents within a given master directory and subdirs.
I saw this: Shell script - search and replace text in multiple files using a list of strings.
And this: How to change all occurrences of a word in all files in a directory
I have tried this:
grep -r "my-silly-home-page-name.html" .
This finds the lines on which the text exists, but now I would like to substitute 'my-silly-home-page-name' for 'index'.
How would I do this with sed or perl?
Or do I even need sed/perl?
Something like:
grep -r "my-silly-home-page-name.html" . | sed 's/$1/'index'/g'
?
Also; I am trying this with perl, and I try the following:
perl -i -p -e 's/my-silly-home-page-name\.html/index\.html/g' *
This works, but I get an error when perl encounters directories, saying "Can't do inplace edit: SOMEDIR-NAME is not a regular file, <> line N"
Thanks,
jml
find . -type f -exec \
perl -i -pe's/my-silly-home-page-name(?=\.html)/index/g' {} +
Or if your find doesn't support -exec +,
find . -type f -print0 | xargs -0 \
perl -i -pe's/my-silly-home-page-name(?=\.html)/index/g'
Both pass to Perl as arguments as many names at a time as possible. Both work with any file name, including those that contains newlines.
If you are on Windows and you are using a Windows build of Perl (as opposed to a cygwin build), -i won't work unless you also do a backup of the original. Change -i to -i.bak. You can then go and delete the backups using
find . -type f -name '*.bak' -delete
This should do the job:
find . -type f -print0 | xargs -0 sed -e 's/my-silly-home-page-name\.html/index\.html/g' -i
Basically it gathers recursively all the files from the given directory (. in the example) with find and runs sed with the same substitution command as in the perl command in the question through xargs.
Regarding the question about sed vs. perl, I'd say that you should use the one you're more comfortable with since I don't expect huge differences (the substitution command is the same one after all).
There are probably better ways to do this but you can use:
find . -name oldname.html |perl -e 'map { s/[\r\n]//g; $old = $_; s/oldname.txt$/newname.html/; rename $old,$_ } <>';
Fyi, grep searches for a pattern; find searches for files.
I have a perl script which is used to process some data files from a given directory. I have written below bash script to look for the last updated file in the given directory and process that file.
cd $data_dir
find \( -type f -mtime -1 \) -exec ./script.pl {} \;
Sometimes, user copied multiple files to the data dir and hence the previous one skipped. The perl script execute only the last updated file. Can you please suggest me how to fix this using bash script.
Try
cd $data_dir
find \( -type f -mtime -1 \) -exec ./script.pl {} +
Note the termination of -exec with a + vs your \;
From the man page
-exec command {} +
This variant of the -exec action runs the specified command on the selected files, but the command line is built by appending each selected file name at the end;
Now that you'll have one or more file names passed into your perl script, you can alter your perl script to iterate over each passed in file name.
If I understood the question correctly, you need to process any files that were created or modified in a directory since the last time your script was run.
In my opinion find is not the right tool to determine those files, because it has no notion of which files it has already seen.
Using any of the -atime/-ctime/-mtime options will either produce duplicates if you run your script twice in the specified period, or miss some files if it is not executed at the right time. The timing intricacies of using these options for something like this are not easy to deal with.
I can propose a few alternatives:
a) Use three directories instead of one: incoming/ processing/ done/. Your users should only be allowed to put files in incoming/. You move any files in there to processing/ with a simple mv incoming/* processing/ before running your perl script. Then you move them from processing/ to done/ when its over.
In my opinion this is the simplest and best solution, and the one used by mail servers etc when dealing with this issue. If I were you and there were not any special circumstances preventing you from doing this, I'd stop reading here.
b) Have your finder script touch a special file (e.g. .timestamp, perhaps in a different directory, so that your users will not tamper with it) when it's done. This will allow your script to remember the last time it was run. Then use
find \( -cnewer .timestamp -o -newer .timestamp \) -type f -exec ./script.pl '{}' ';'
to run your perl script for each file. You should modify your perl script so that it can run repeatedly with a different file name each time. If you can modify it to accept multiple files in one go, you can also run it with
find \( -cnewer .timestamp -o -newer .timestamp \) -type f -exec ./script.pl '{}' +
which will minimise the number of ./script.pl processes. Take care to handle the first run of the find script, when the .timestamp file is missing. A good solution would be to simply ignore it by not using the -*newer options at all in that case. Also keep in mind that there is a race condition where files added after find was started but before touching the timestamp file will not be processed.
c) As a variation of (b), have your script update the timestamp with the time of the processed file that was created/modified most recently. This is tricky, because find cannot order its output on its own. You could use a wrapper around your perl script to handle this:
#!/bin/bash
for i in "$#"; do
find "$i" \( -cnewer .timestamp -o -newer .timestamp \) -exec touch -r '{}' .timestamp ';'
done
./script.pl "$#"
This will update the timestamp if it is called to process a file with a newer mtime or ctime, minimising (but not eliminating) the race condition. It is however somewhat awkward - unavoidable since bash's [[ -nt option seems to only check the mtime. It might be better if your perl script handled that on its own.
d) Have your script store each processed filename and its timestamps somewhere and then skip duplicates. That would allow you to just pass all files in the directory to it and let it sort out the mess. Kinda tricky though...
e) Since your are using Linux, you might want to have a look at inotify and the inotify-tools package - specifically the inotifywait tool. With a bit of scripting it would allow you to process files as they are added in the directory:
inotifywait -e MOVED_TO -e CLOSE_WRITE -m -r testd/ | grep --line-buffered -e MOVED_TO -e CLOSE_WRITE | while read d e f; do ./script.pl "$f"; done
This has no race conditions, as long as your users do not create/copy/move any directories rather than just files.
The perl script will only execute against the file which find gives it. Perhaps you should remove the -mtime -1 option from the find command so that it picks up all the files in the directory?
I am interested into getting into bash scripting and would like to know how you can traverse a unix directory and log the path to the file you are currently looking at if it matches a regex criteria.
It would go like this:
Traverse a large unix directory path file/folder structure.
If the current file's contents contained a string that matched one or more regex expressions,
Then append the file's full path to a results text file.
Bash or Perl scripts are fine, although I would prefer how you would do this using a bash script with grep, awk, etc commands.
find . -type f -print0 | xargs -0 grep -l -E 'some_regexp' > /tmp/list.of.files
Important parts:
-type f makes the find list only files
-print0 prints the files separated not by \n but by \0 - it is here to make sure it will work in case you have files with spaces in their names
xargs -0 - splits input on \0, and passes each element as argument to the command you provided (grep in this example)
The cool thing with using xargs is, that if your directory contains really a lot of files, you can speed up the process by paralleling it:
find . -type f -print0 | xargs -0 -P 5 -L 100 grep -l -E 'some_regexp' > /tmp/list.of.files
This will run the grep command in 5 separate copies, each scanning another set of up to 100 files
use find and grep
find . -exec grep -l -e 'myregex' {} \; >> outfile.txt
-l on the grep gets just the file name
-e on the grep specifies a regex
{} places each file found by the find command on the end of the grep command
>> outfile.txt appends to the text file
grep -l -R <regex> <location> should do the job.
If you wanted to do this from within Perl, you can take the find commands that people suggested and turn them into a Perl script with find2perl:
If you have:
$ find ...
make that
$ find2perl ...
That outputs a Perl program that does the same thing. From there, if you need to do something that easy in Perl but hard in shell, you just extend the Perl program.
find /path -type f -name "*.txt" | awk '
{
while((getline line<$0)>0){
if(line ~ /pattern/){
print $0":"line
#do some other things here
}
}
}'
similar thread
find /path -type f -name "outfile.txt" | awk '
{
while((getline line<$0)>0){
if(line ~ /pattern/){
print $0":"line
}
}
}'