chraebsli to Programmer [email protected] • 1 year agoTouch a file in Linuxprogramming.devimagemessage-square94fedilinkarrow-up11.2Karrow-down131
arrow-up11.17Karrow-down1imageTouch a file in Linuxprogramming.devchraebsli to Programmer [email protected] • 1 year agomessage-square94fedilink
minus-square@[email protected]linkfedilinkEnglish21•edit-21 year agoFeels dangerous to run. What happens if the file already exists and has something important in it? touch -a is probably better
minus-square@[email protected]linkfedilink9•1 year agoThe other command could just be printf '' >> file to not overwrite it. Or even simpler >>file and then interrupt
minus-square@[email protected]linkfedilink6•1 year ago.“:>>” is “append null” right? Do you get a file with a single ASCII NUL or is it truly empty?
minus-squareTrailblazing Braille Taserlinkfedilink14•1 year agoNot really. I believe : is the “true” builtin. So it’s like running a program that exits with zero and writes nothing to stdout. The >> streams the empty stdout into the named file.
minus-square@[email protected]linkfedilink4•edit-21 year ago$ :|wc -c 0 $ touch /tmp/f; :>>/tmp/f; wc -c /tmp/f 0 /tmp/f
minus-square@[email protected]linkfedilink3•1 year agothat’s awesome, did not know about that handy operator!
minus-square@[email protected]linkfedilink3•1 year agoYeah! it’s basically a noop, I use it as a placeholder when I’m writing a script, since bash doesn’t accept code blocks with no commands
Feels dangerous to run. What happens if the file already exists and has something important in it?
touch -ais probably betterThe other command could just be
printf '' >> fileto not overwrite it. Or even simpler>>fileand then interruptor
:>>filethen you don’t need to interrupt.“:>>” is “append null” right? Do you get a file with a single ASCII NUL or is it truly empty?
Not really. I believe : is the “true” builtin. So it’s like running a program that exits with zero and writes nothing to stdout. The >> streams the empty stdout into the named file.
$ :|wc -c 0 $ touch /tmp/f; :>>/tmp/f; wc -c /tmp/f 0 /tmp/f
that’s awesome, did not know about that handy operator!
Yeah!
it’s basically a noop, I use it as a placeholder when I’m writing a script, since bash doesn’t accept code blocks with no commands