Comment by sieve

4 years ago

This is a UI/UX problem that I only face when dealing with shells and shell scripts. Never had any issues when spawning processes from within languages/runtimes that support sane argument arrays.

sh, bash and cmd.exe are shit. The shell needs serious rethinking.

12 comments

sieve

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necovek  4 years ago

This is a difference between $@ and "$@" (note the quotes):

  $ cat proba.sh 
  #!/bin/sh
  echo "Using quotes:"
  for i in "$@"; do echo "$i"; done
  echo "No quotes:"
  for i in $@; do echo "$i"; done
  $ ./proba.sh "ho ho ho"
  Using quotes:
  ho ho ho
  No quotes:
  ho
  ho
  ho

Joker_vD  4 years ago

I see that there are lots of comments about problems of TAB-completions with filenames with spaces in this comment section and I am frankly puzzled: both Bash and cmd.exe actually TAB-complete those perfectly fine, inserting quoting where it's needed.

  • tremon  4 years ago

    And where it isn't needed. If you have a path that contains a variable and a space, bash will happily escape the $, making the path invalid. See the following:

      $ cd $HOME
  $ mkdir my\ dir
  $ ls my[tab]
  $ cd /
  $ ls $HOME/my[tab]
  ls: cannot access '$HOME/my dir/': No such file or directory

    That error is because when you press [tab], bash changed the path to \$HOME/my\ dir/ but that isn't obvious from the output and I couldn't find a proper way to include the tab-expanded result in the transcript.

    (edit: this is on GNU bash, version 4.3.48(1)-release but I've seen this behaviour for years)

    • Joker_vD  4 years ago

      Depends on the Bash version, I guess? Mine is 4.4.20(1) and when I do "cd $HOME/my[TAB]", it replaces the input line with "cd /home/joker/my\ dir/", and pressing [ENTER] changes the directory to '/home/joker/my dir', as can be seen from the prompt.

      1 reply →

  • necovek  4 years ago

    I seem to remember bash losing preferred escaping when TAB-completing, but can't reproduce it now with 5.0.17.

    Eg. you'd type `ls -l "Spaced [TAB]` and it would turn it into `ls -l Spaced\ Name`. I remember similar annoyances with other special shell characters (eg. single quotes, dollars, slashes), but that all seems to behave sane now.

    • xyzzy_plugh  4 years ago

      I didn't even know this was a thing, but can't say I've ever preferred an escape style. I actually use backslashes a fair bit, usually just with spaces. I tend to reserve double quotes for variable or shell expansion, explicitly.

      1 reply →

  • sieve  4 years ago

    > inserting quoting where it's needed

    You have to remind yourself to do this manually in scripts if you don't want to see lines full of "No such file or directory."

    One of the reasons the shell is broken is because the character they use as an argument array member separator is something that regular people use to distinguish between two words, such as in a file name.

    • Joker_vD  4 years ago

      Well, writing scripts would be much less painful if $VARNAME did not explode into pieces by default. Alas, this ship has sailed long ago.

      1 reply →