Insert header in a csv file with command line Windows

Question

I have a .csv file with some data, for example:

a | b | c | d | e
f | g | h | i | f

I would like to insert a header in this file to indicate each field:

h1 | h2 | h3 | h4 | h5
a | b | c | d | e
f | g | h | i | l

I would like to do it from the Windows command line, how can I do?

Answer 1

First, write the header to a new text file (escape the pipe symbol | using ^)

echo h1 ^| h2 ^| h3 ^| h4 ^| h5 > combined.csv

Then append the original file to this newly created file:

type originalfile.csv >> combined.csv

At last, you overwrite the original file with the content of the new file (including the header line)

type combined.csv > originalfile.csv
--or--
move /Y combined.csv originalfile.csv

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Based on these answers: using batch echo with special characters and Easiest way to add a text to the beginning of another text file in Command Line (Windows)

Answer 2

You can use Miller and run

mlr --csv --implicit-csv-header --fs "|" label h1,h2,h3,h4,h5 input.csv

to have

h1|h2|h3|h4|h5
a|b|c|d|e
f|g|h|i|f

• --csv to set the format
• --implicit-csv-header to declare that the input has no heading
• --fs "|" to set the field separator
• label h1,h2,h3,h4,h5 to set the heading