CODEWITHSUNDEEP
unixsedterminal
astromonerd
astromonerd

Reputation: 937

How to cat using part of a filename in terminal?

I'm using terminal on OS 10.X. I have some data files of the format:

mbh5.0_mrg4.54545454545_period0.000722172513951.params.dat
mbh5.0_mrg4.54545454545_period0.00077271543854.params.dat
mbh5.0_mrg4.59090909091_period-0.000355232058085.params.dat
mbh5.0_mrg4.59090909091_period-0.000402015664015.params.dat

I know that there will be some files with similar numbers after mbh and mrg, but I won't know ahead of time what the numbers will be or how many similarly numbered ones there will be. My goal is to cat all the data from all the files with similar numbers after mbh and mrg into one data file. So from the above I would want to do something like...

cat mbh5.0_mrg4.54545454545*dat > mbh5.0_mrg4.54545454545.dat
cat mbh5.0_mrg4.5909090909*dat > mbh5.0_mrg4.5909090909.dat

I want to automate this process because there will be many such files. What would be the best way to do this? I've been looking into sed, but I don't have a solution yet.

Upvotes: 0

Views: 155

Answers (2)

Johan
Johan

Reputation: 389

It's not 100% clear to me what you're trying to achieve here but if you want to aggregate files into a file with the same number after "mbh5.0_mrg4." then you can do the following.

ls -l mbh5.0_mrg4* | awk '{print "cat " $9 " > mbh5.0_mrg4." substr($9,12,11) ".dat" }' | /bin/bash

The "ls -s" lists the file and the "awk" takes the 9th column from the result of the ls. With some string concatenation the result is passed to /bin/bash to be executed.

This is a linux bash script, so assuming you have /bind/bash, I'm not 100% famililar with OS X. This script also assumes that the number youre grouping on is always in the same place in the filename. I think you can change /bin/bash to almost any shell you have installed.

Upvotes: 0

glenn jackman
glenn jackman

Reputation: 247012

for file in *.params.dat; do
    prefix=${file%_*}
    cat "$file" >> "$prefix.dat"
done

This part ${file%_*} remove the last underscore and following text from the end of $file and saves the result in the prefix variable. (Ref: http://www.gnu.org/software/bash/manual/bashref.html#Shell-Parameter-Expansion)

Upvotes: 3

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