I have two .csv files that I need to match based on column 1.

The two file structures look like this.


gopAga1_00004004-RA,1122.825534,    -2.497919969,   0.411529843

gopAga1_00010932-RA,440.485381, 1.769511316,    0.312853434 

gopAga1_00007012-RA, 13.37565185,   -1.973108929,   0.380227982



gopAga1_00004004-RA,    ENSACAP00000013845

gopAga1_00009937-RA,    ENSACAP00000000905

gopAga1_00010932-RA,    ENSACAP00000003279

gopAga1_00000875-RA,    ENSACAP00000000296

gopAga1_00010837-RA,    ENSACAP00000011919

gopAga1_00007012-RA,    ENSACAP00000012682

gopAga1_00017831-RA,    ENSACAP00000016147

gopAga1_00005588-RA,    ENSACAP00000011117


This is my current command that I am running using join:

This is formatted from what I have also read on the following threads here

join -1 1 -2 1 -t , -a 1 -e "NA" -o "2.2,1.1,1.2,1.3" <(sort -k 1 healthy_vs_unhealthy_de.csv) <(sort RBH.csv) > output.txt

However, every time I run this prompt it only writes the first row to output.

Anyone know why my code is running like this and not actually merging the two files based on the GOP ID?

2 Answers 2


we should specify delimiter as comma for sort

# join -1 1 -2 1 -t , -a 1 -e "NA" -o "2.2,1.1,1.2,1.3" <(sort -t',' -k 1 healthy_vs_unhealthy_de.csv) <(sort -t',' RBH.csv)
ENSACAP00000013845,gopAga1_00004004-RA,1122.825534,    -2.497919969
ENSACAP00000012682,gopAga1_00007012-RA, 13.37565185,   -1.973108929
ENSACAP00000003279,gopAga1_00010932-RA,440.485381, 1.769511316
  • Thanks for the input, I've included that in my prompt. Unfortunately, my output file only writes the first row still. It may have to do with how file 2 was prepared? It was downloaded as an excel file and converted into a csv file whereas, file 1 was exported as a csv file from R.
    – cdxun
    Commented Jun 26, 2018 at 20:55
  • 1
    @cdxun: you could try converting file 2 to "unix format" with dos2unix first.
    – FloHimself
    Commented Jun 27, 2018 at 6:26

As Siva correctly points out, your main issue is that the sort utility is being called incorrectly. However, you additionally have issues with embedded whitespaces that could possibly prove problematic for the sorting.

Switching to using the csvkit tools for parsing and generally working with CSV files on the command line, we could use csvjoin to perform the join. This is assuming that there are no empty lines in the input data. If there are empty lines, then remove these first, possibly by filtering the files through grep -vx '[[:blank:]]*'.

csvjoin --no-header-row --skipinitialspace --columns=1 file1 file2

or, using short options,

csvjoin -HS -c 1 file1 file2

Given the data in your question, this would output


Note that it adds headers that you may want to remove later (possibly using tail -n +2).

To rearrange this (and drop the third column), we may use csvcut. We also drop the added header with tail as just mentioned:

csvjoin -HS -c 1 file1 file2 |
csvcut -c 5,1-3 |
tail -n +2

... which would result in


The columns used with csvcut could also have been specified using the temporary headers, e.g. as -c b2,a,b,c or as a combination like -c b2,1-3.

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