Not always

$ cat a | while read line; do echo $line; done

#!/usr/bin/env bash

PUPPETEER_PRODUCT=firefox npm install -g md-to-pdf

$ < a while read line; do echo $line; done

-bash: syntax error near unexpected token `do'

 Tyler

On Fri, Dec 4, 2020 at 3:17 PM Niklas Karlsson <nikke.karlsson@gmail.com> wrote:

< file grep foo works.

Niklas

Den fre 4 dec. 2020 kl 14:16 skrev Tyler Adams <coppero1237@gmail.com>:

I find cat file | grep foo simpler because it reads Left to Right.

 Tyler

On Fri, Dec 4, 2020 at 1:34 PM Andy Kosela <akosela@andykosela.com> wrote:

On 12/4/20, arnold@skeeve.com <arnold@skeeve.com> wrote:
> Dan Cross <crossd@gmail.com> wrote:
>
>> This has always struck me as particularly elegant in scripts. Consider:
>>
>>     cat "$@" | whatever
>>
>> (Or you may prefer `cat $* | whatever`)
>>
>> Now one's script can take any number of file arguments or stdin, even if
>> the filter does not.
>
> I think Dan has hit the heart of the matter. People are used to using
> cat for multiple files to start pumping data down a pipeline, so they
> continue to do so even when there's only one file.
>

The classic example is:

  $ cat file | grep foo

instead of the simpler:

  $ grep foo file

It appears cat(1) and pipe(7) are deeply ingrained in people's brains.

--Andy