qazerlab / thepipe

Table Header Excluded Pipe

Table Header Excluded Pipe

When you pipe stdout of some command to another one, every line is fed to the latter. If the output of the first one is a table, its first line (the header) is processed by the second command along with the table content, which is frequently not the desired behavior.

Table Header Excluded Pipe (thepipe) echoes the first line of stdin received from somewhere as is and pipes the rest of the input to the child command, as the usual pipe does, for example:

$ ps | thepipe sed 's!pts/!!'
    PID TTY          TIME CMD
  14107 5    00:00:00 bash
  14128 5    00:00:00 ps
  14129 5    00:00:00 thepipe
  14130 5    00:00:00 thepipe

The table header stays untouched while the table content is processed through sed.

Given that the most frequent use of this tool is filtering the content of the table with grep, there is a wrapper thegrep, which does exactly what thepipe grep would do:

$ docker images | thegrep postgres
REPOSITORY          TAG                 IMAGE ID            CREATED             SIZE
postgres            latest              c96f8b6bc0d9        2 weeks ago         314MB

Build

To build thepipe you need a Rust toolchain.

Once you have it on your machine, you can build thepipe by running

cargo build --release

The resulting binary is target/release/thepipe.

To install it into your system, run

sudo ./install

This will place thepipe and thegrep into your /usr/bin.