CODEWITHSUNDEEP
bash
Software_t
Software_t

Reputation: 586

How can I sort input that sended by "cat" in pipeline to function?

How can I sort the input from cat like that explained the following code (?) :

function sort_input {
output_filename=${1}
# How can I sort the input (What that this function get from `cat`) into `output_filename` ?
}

cat ${1} | sort_input ${1}  # I don't want to change this line!

The script get as argument: name of a file.

Clarification: How can I write sort_input function, so that, this function will sort the input that sended by cat ${1} [And will insert the result of the sorting to the file output_filename] ?

Upvotes: 0

Views: 149

Answers (2)

chepner
chepner

Reputation: 531908

The function you want is pretty simple:

sort_input () {
    sort -o "$1"
}

sort will inherit its standard input from the function, so sort_input foo < foo is identical to sort -o foo < foo. -o involves a temporary file internally so that it works even if you are using the same file for input and output.

Upvotes: 1

Software_t
Software_t

Reputation: 586

More option: (without a temp file)
After that I see the answer of @PesaThe , I think that we can do it without a temp file, like that: 

#!/usr/bin/env bash

sort_input() { 
    sort /dev/stdin > "$1"
}

cat "$1" | sort_input "$1"

Upvotes: 0

Related Questions