[TUHS] The UNIX Command Language (1976)

[Tyler Adams]

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 at gmail.com>
wrote:

> < file grep foo works.
>
> Niklas
>
> Den fre 4 dec. 2020 kl 14:16 skrev Tyler Adams <coppero1237 at 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 at andykosela.com>
>> wrote:
>>
>>> On 12/4/20, arnold at skeeve.com <arnold at skeeve.com> wrote:
>>> > Dan Cross <crossd at 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
>>>
>>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://minnie.tuhs.org/pipermail/tuhs/attachments/20201204/b8c0f3f8/attachment.htm>