Zsh script improvements

[nthapaliya]

I'm using macOS, but I've installed gnu coreutils from homebrew. By default, in order to avoid conflicts with system utils, they are prefixed with a g, eg. ls is installed as gls and so on.

There is a zsh module (from prezto) that wraps these utils in functions so that I can use them without the prefix in interactive shells. For example:

$ which -a cat
cat () {
        '/usr/local/bin/gcat' "$@"
}
/bin/cat

And so on.

This PR fixes some issues I encountered with this setup. In particular [ and cat. I've also tested these changes on 'vanilla' zsh (using system utils, no gnu-coreutils) and nothing breaks.

Bug from first commit:

Autocomplete with **<tab> would print an error like:

vi **/usr/local/bin/g[: missing argument after ‘-d’

From the bsd man page for test. I assume this is the same for gnu-test.

BUGS
     Both sides are always evaluated in -a and -o.  For instance, the writable status of file will be tested by the fol-
     lowing command even though the former expression indicated false, which results in a gratuitous access to the file
     system:
           [ -z abc -a -w file ]
     To avoid this, write
           [ -z abc ] && [ -w file ]

To reproduce the bug from the second commit:

I tested by starting a clean zsh session with ZDOTDIR=/dev/null zsh

$ source .fzf.zsh
$ which cat # making sure cat is /bin/cat (default)
$ ssh **<tab> # works
# now define your own cat wrapper
# you can just wrap the default cat, you still get the bug.
$ cat() { '/bin/cat' "$@" }

# typing in ssh ** and hitting tab will now give us
MacBook-Pro% ssh **cat: /dev/fd/12: Bad file descriptor
cat: /dev/fd/13: Bad file descriptor
cat: /dev/fd/14: Bad file descriptor
MacBook-Pro% ssh **

[junegunn]

I see, thanks. What do you think about the following? Smaller diff.

diff --git a/shell/completion.zsh b/shell/completion.zsh
index cef8afa..0be5ad1 100644
--- a/shell/completion.zsh
+++ b/shell/completion.zsh
@@ -44,7 +44,7 @@ __fzf_generic_path_completion() {
   setopt localoptions nonomatch
   dir="$base"
   while [ 1 ]; do
-    if [ -z "$dir" -o -d ${~dir} ]; then
+    if [[ -z "$dir" || -d ${~dir} ]]; then
       leftover=${base/#"$dir"}
       leftover=${leftover/#\/}
       [ -z "$dir" ] && dir='.'
@@ -111,7 +111,7 @@ _fzf_complete_telnet() {

 _fzf_complete_ssh() {
   _fzf_complete '+m' "$@" < <(
-    cat <(cat ~/.ssh/config /etc/ssh/ssh_config 2> /dev/null | command grep -i '^host' | command grep -v '*') \
+    command cat <(cat ~/.ssh/config /etc/ssh/ssh_config 2> /dev/null | command grep -i '^host' | command grep -v '*') \
         <(command grep -oE '^[^ ]+' ~/.ssh/known_hosts | tr ',' '\n' | awk '{ print $1 " " $1 }') \
         <(command grep -v '^\s*\(#\|$\)' /etc/hosts | command grep -Fv '0.0.0.0') |
         awk '{if (length($2) > 0) {print $2}}' | sort -u

[nthapaliya]

Yeah, yours is better. I'll make the change.

[nthapaliya]

OK, I've updated the commits.

[junegunn]

Merged, thanks!