How To Split or Cut A File Vertically(Column wise)

In Unix environment it’s often required to print specific columns from a file. If the rows of file are having some proper delimiters then other Unix command like awk come into picture and quite handy. But if say you want to print out the 5^th character and then 7^th to 16^th character, then other commands fail and in such situations the cut command comes to rescue. Here is short primer of cut command.

For our example I have taken a file named as list. Its output is pasted below:

[ganesh@host ~]$ cat list

-rwxr-xr-x|1|root|root|1904|Nov|10|2007|crond

-rwxr-xr-x|1|root|root|1505|Jan|6|2007|dc_client

-rwxr-xr-x|1|root|root|1347|Jan|6|2007|dc_server

Let’s say you want the 4^th column from the above output.

Use the below command:

cut -c4 list

Here c signifies the number of column.

The output is:

[ganesh@host ~]$ cut -c4 list

x

Now let’s say you want 3^rd to 10^th column. You can specify m^th to n^th fields as m-n as you’ll see in examples. Use the below command:

cut -c3-10 list

[ganesh@host ~]$ cut -c3-10 list

wxr-xr-x

wxr-xr-x

wxr-xr-x

Now let’s say you want 4^th to 16^th column and everything after 20^th column

Use the below command:

cut -c4-10,16- list

[ganesh@host ~]$ cut -c4-10,16- list

xr-xr-xot|root|1904|Nov|10|2007|crond

xr-xr-xot|root|1505|Jan|6|2007|dc_client

xr-xr-xot|root|1347|Jan|6|2007|dc_server

Remember there is no space provided between multiple cuts taken from a file. You see -xot in the output. xr-xr-x is one output and ot|root|1904|Nov|10|2007|crond is another output.

Now let’s say the file is delimited by a separator e.g ‘|’. Here cut gives you a special option ‘-d’. It’s used to specifiy the delimiter and then the filed on it.

The following example makes it a little bit clear.

Suppose you want to get the 1^st to 3^rd field, 5^th to 6^th field and then 8^th onwards all fields, based on | as delimiter.

Use the command:

cut -d ‘|’ -f 1-3,5-6,8- list

[ganesh@host ~]$ cut -d ‘|’ -f 1-3,5-6,8- list

-rwxr-xr-x|1|root|1904|Nov|2007|crond

-rwxr-xr-x|1|root|1505|Jan|2007|dc_client

-rwxr-xr-x|1|root|1347|Jan|2007|dc_server

In some future post I’ll write about pasting the outputs.