CODEWITHSUNDEEP
regexgrep
bartonm
bartonm

Reputation: 1650

grep through an explicit filelist

Stack,

We have many files in our library that were never used in subsequent projects. We are now at a development phase where we can do some good housekeeping and carefully remove unused library code. I am trying to optimize my grep command, it's current implementation is quite slow.

grep --include=*.cpp --recursive --files-with-matches <library function name> <network path to subsequent projects>

The main reason is that the projects path is expansive and the bulk of the time is spent just navigating the directory tree and applying the file mask. This grep command is called many times on the same set of project files.

Rather than navigating the directory tree every call, I would like to grep to reference a static filelist stored on my local disk.

Something akin to this:

grep --from-filelist=c:\MyProjectFileList.txt

The MyProjectFileList.txt would be:

\\server1\myproject1\main.cpp
\\server1\myproject1\func1.cpp
\\server1\myproject2\main.cpp
\\server1\myproject2\method.cpp

Grep would apply the pattern-expression to contents of each of those files. Grep output would be the fully qualified path of the project file that is uses a specific library function.

Grep commands for specific library functions that return no project files are extraneous and can be deleted.

How do you force grep to scan files from an external filelist stored in a text file? (Thereby removing directory scanning.)

Upvotes: 2

Views: 1091

Answers (3)

grid
grid

Reputation: 323

Try the following:

while read line; do echo -e "$line"; done < list_of_files.txt | xargs -0 grep **YOUR_GREP_ARGS_HERE**

or in a Windows environment with Powershell installed try...

Get-Content List_of_files.txt | Foreach-Object {grep $_ GREP_ARGS_HERE}

Upvotes: 1

BeniBela
BeniBela

Reputation: 16917

I googled for windows args and found this:

FOR /F %k in (filelist.txt) DO grep yourgrepargs  %k

(but I use linux, no idea if it works)

Upvotes: 0

arkascha
arkascha

Reputation: 42925

Try around a little using the 'xargs' command and pipes ("|").

Upvotes: 1

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