piping stdout of cat to kill's stdin

If I have the pid of some process stored in a text file, let's call it program.pid, and I want to end that process via the kill command, how come I can't do this:

bash:$ cat program.pid | kill

But if cat program.pid, and just type the output into the kill command, it works and I stop the process.  Why can't I pipe the output from cat to kill?

>>40
Congratulations, you've mastered man cat like a champ.
Now see if you can figure out how filesystems work, and why ext3 only requires that you update x - 1 blocks to concatenate files, where x is the number of files you're concatenating, whereas your little cat strategy requires that you read all of the files in their entirety, and then write them all to disk again in their entirety.

tl;dr: Your script sucks balls, Ubantoofag.

>>37
>>39
Learn to shell.

>>41
YOU'VE ANGERED A FUCKING [b][u][o]EXPERT [sup]UBANTU[/sup] SYSOP[/o][/u][/b]

>>43
lol [failcodetag]

>>41
no sorry, you're just a troll. GNU cp cannot concatenate files.

ps. lol @ x-1 blocks. knothxbi.

>>1-9999

You all fail, faggots

>>46 failed himself

Can we get back on topic please?  What's a failsafe way of finding out if a program can read from stdin or not?

What's stdin?

>>48
1. Read the man pages.
2. Try it.

It's not that fucking hard.

>>50
What's man pages?

>>51
Back to /b/, please.

>>52
What's /b/?

>>53
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>>53
Back to man pages, please.

>>55
what is >>53?

I thought /b/ was a person not a place

>>57
what is Anonymous?

PLEASE STOP THREADRESSING THIS

>>58
What are you talking aboot?

I still don't see the difference.

H<sup>OLY SHIT I L_OVE ICECREAM

_Marijuana MUST be legalized.

BBCode MASTERS smoke WEED!</sup>

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