21–30 of 62 posts
Don't do this: cat file | wc -l => wc -l head -n 5 file cat file | awk '{print $1}' => awk '{print $1}' file cat file | sort => sort file Do this instead: cat file | wc -l => The front-cat abuse is all about the order. The effective solution needs to keep the relative order of arguments.
Or just use cat and spend your brainpower on interesting, useful, and/or worthwhile topics. It boggles my mind that anyone cares about this.
Earlier quoted context omitted.
Or just use cat and spend your brainpower on interesting, useful, and/or worthwhile topics. It boggles my mind that anyone cares about this.
Probably, but knowing that redirection operators can be freely moved within normal arguments [EDIT: thank ButlerianJihad for pursuing me to make this more accurate] is useful.
cat file > /dev/null 2>&1
Earlier quoted context omitted.
Probably, but knowing that redirection operators can be freely moved within normal arguments [EDIT: thank ButlerianJihad for pursuing me to make this more accurate] is useful.
They are actually not “order-independent”, and their L-R parsing/processing is why constructs such as cat file > /dev/null 2>&1 work as intended.
2>&1 >/dev/null cat file
if this wanton abuse of cat(1) doesn't stop, we're on track to run out of PIDs by 2031! Just because Unix makes it cheap and easy to fork doesn't mean you have to! (who gives even a single shit, my god)
Earlier quoted context omitted.
They are actually not “order-independent”, and their L-R parsing/processing is why constructs such as cat file > /dev/null 2>&1 work as intended.
funny enough, 2>&1 >/dev/null cat file appears to yield the same output. So i wonder where the not "order-independent" chimes in.
It does not yield the "same output", and here is why: if you cause your command to actually produce output on stderr (fd 2) it will appear as terminal output, because you have actually succeeded in "redirecting" stderr to wherever stdout (fd 1) was pointing initially.
Personally, when I'm exploring, I build a command line iteratively. Cat the file to see the content, pipe to grep to get the lines I want, sed/awk/cut/etc to finagle from there.