CODEWITHSUNDEEP
bash
cpwah
cpwah

Reputation: 141

Merge two csv files in bash

I have two csv files.

Columns of the first file

col1, col2, col3,......col4095, col4096, col4097

Columns of the second file

col1, col2, col3,......,col4095, col4096, col4097

Expected output - the last column of the first file is discarded

col1, col2, col3.......,col4095. col4096, col1, col2, col3....col4095, col4096, col4097

Both files have the same number of rows, I want to merge the two files into one file.

Upvotes: 2

Views: 15422

Answers (2)

heemayl
heemayl

Reputation: 42147

With only awk:

awk -F ',[[:blank:]]*' 'NR==FNR {for (i=1;i<NF;i++) out=out$i", " ; next} \
                        {out=out$0} END{print out}' f1.csv f2.csv

  • -F ',[[:blank:]]*' sets the field separator as , followed by any number of space/tab

  • NR==FNR will be true for the first file only, then {for (i=1;i<NF;i++) out=out$i", " ; next} will be executed, which will iterate over, and concatenate all the fields but the last one in variable out

  • The record of the second file would be concatenated to the variable out -- {out=out$0}

  • Finally, the value of variable out is printed -- END{print out}

Example:

% cat f1.csv                                                                                                        
col1, col2, col3,......col4095, col4096, col4097

% cat f2.csv 
col1, col2, col3,......,col4095, col4096, col4097

% awk -F ',[[:blank:]]*' 'NR==FNR {for (i=1;i<NF;i++) out=out$i", " ; next} {out=out$0} END{print out}' f1.csv f2.csv 
col1, col2, col3, ......col4095, col4096, col1, col2, col3,......,col4095, col4096, col4097

Upvotes: 0

sat
sat

Reputation: 14979

Use paste :

paste -d, f1.csv f2.csv > out.csv

To ignore last column of first file:

awk -F, 'NF-=1' OFS=, f1.csv | paste -d, - f2.csv > out.csv

Upvotes: 13

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