In Linux, if I have a bunch of text files is there a simple script to merge them into one file?

For example suppose I have 1.csv, 2.c开发者_Python百科sv, ... , 20.csv. Is there a simple shell script where I can merge everything into merged.csv?

Use cat to concatenate them.

cat *.csv > merged.csv

As @sarnold points out this will concatenate them out of order. If that's important, use his for loop suggestion, or this xargs pipeline:

ls *.csv | sort -n | xargs cat > merged.csv

If you're looking to merge files by appending the lines from one on to the end of the lines of the other, then you're looking for paste.

For example, if file1 contains:

1,One
2,Two

And file2 contains:

A,B,C
D,E,F

You could run paste -d , file1 file2 to get this:

1,One,A,B,C
2,Two,D,E,F

The simple answer:

cat *.csv > merged.csv

will sort 1.csv 10.csv 2.csv 20.csv 3.csv.... If you want them sorted by number, it takes a bit more work:

for i in `seq 1 20`; do cat ${i}.csv >> merged.csv ; done

cat {1..20}.csv > merged.csv

It's what cat was made for! Note that I've used a bash-ism in the {1..20} sequence.