Pipelines

pipeline

command1 | command2 ...
time [-p] command1 [| command2 ...]

• the output of each command is connected to the inpot of the next command
• the exit code of the pipe is the exit code of the last command
• if a exclamation mark (!) precedes the first command of the pipe, the exit status of the pipe will be negated
• every command is executed as a separate process (i.e. in a subshell)

zcat patchfile.gz | patch -p1

zcat nice.1.gz | groff -T ascii -m an | less
FIXME: um keine Steuerzeichen im Output zu haben...

cat /etc/shells | grep "/bin" | wc -l		# UUCA
grep "/bin" /etc/shells | wc -l