Text manipulation with grep or awk

Question

Wondering if somebody can help me with grep or awk. I have 2 files, the first one contains students IDs and a second that contains config files that relates to each student

File 1 (oldstudent.txt)

File 2 (app_path.config)

    /export/home/5678D956/Scripts
    /export/home/5678D956/FTP
    /export/home/5678D956/HomeDirs   
    /export/home/4487984D/Scripts
    /export/home/4487984D/FTP
    /export/home/4487984D/HomeDirs    
    /export/home/45S87954/Scripts
    /export/home/45S87954/FTP
    /export/home/45S87954/HomeDirs      
    /export/home/56898K78/Scripts
    /export/home/56898K78/FTP
    /export/home/56898K78/HomeDirs  
    /export/home/909878S4/Scripts
    /export/home/909878S4/FTP
    /export/home/909878S4/HomeDirs

I would like to have it so that if a student exists in File 1, it comments out their configuration setting and saves as File 3 (app_path_new.config)

    #/export/home/5678D956/Scripts
    #/export/home/5678D956/FTP
    #/export/home/5678D956/HomeDirs
    /export/home/4487984D/Scripts
    /export/home/4487984D/FTP
    /export/home/4487984D/HomeDirs    
    #/export/home/45S87954/Scripts
    #/export/home/45S87954/FTP
    #/export/home/45S87954/HomeDirs      
    #/export/home/56898K78/Scripts
    #/export/home/56898K78/FTP
    #/export/home/56898K78/HomeDirs  
    /export/home/909878S4/Scripts
    /export/home/909878S4/FTP
    /export/home/909878S4/HomeDirs

I have been trying with grep, sed and awk, and don't seem to be going anywhere.

Thanks

For what it's worth, `grep -vf file1 file2` will remove all lines from file 2 that match lines in file 1. So there's a grep solution if you tolerate removal of the lines rather than commenting them out. — stevesliva, Apr 25 '17 at 17:34

RomanPerekhrest · Accepted Answer · 2017-04-25T18:12:55.977

awk approach:

awk 'NR==FNR{a[$1]; next}{if($4 in a) $1="#"$1;}1' OFS="/" oldstudent.txt FS="/" app_path.config

The output:

#/export/home/5678D956/Scripts
#/export/home/5678D956/FTP
#/export/home/5678D956/HomeDirs   
/export/home/4487984D/Scripts
/export/home/4487984D/FTP
/export/home/4487984D/HomeDirs    
#/export/home/45S87954/Scripts
#/export/home/45S87954/FTP
#/export/home/45S87954/HomeDirs      
#/export/home/56898K78/Scripts
#/export/home/56898K78/FTP
#/export/home/56898K78/HomeDirs  
/export/home/909878S4/Scripts
/export/home/909878S4/FTP
/export/home/909878S4/HomeDirs

To redirect the output to the new file add the following to the end of the above command:

> app_path_new.config

score -2 · Answer 2 · answered Apr 25 '17 at 17:30

-2

You can do this with a while loop and sed:

cp app_path.config app_path_new.config
cat oldstudent.txt | 
    while read line
    do
        sed -i "s@.*/$line/.*@# &@g" app_path_new.config
    done

answered Apr 25 '17 at 17:30

Behrooz

41
1

Wow.. Works like a charm. Need to learn sed myself, as it seems very powerful. Thank you very much again – tom1123 Apr 25 '17 at 17:51

score -2 · Answer 3 · answered Apr 25 '17 at 17:32

-2

cp app_path.conf app_path_new.conf
for id in `cat oldstudent.txt`; do sed -i '/'$id'/s@^@#@' app_path_new.conf; done

answered Apr 25 '17 at 17:32

John Diller

65
7

Thanks you very much for taking the time to help out. Works like a charm – tom1123 Apr 25 '17 at 17:53

Text manipulation with grep or awk

3 Answers3