One helpful feature of R is being able to use "?<function>" to quickly look up functions, without having to type out "help("<function>")".
Is it possible to implement a similar behavior in shell (e.g. bash or zsh), using a non-reserved character?
That is, somecommand (no space) triggering "man somecommand"
Perhaps, for bash
command_not_found_handle() {
if [[ $1 != Z* ]]; then
echo "$1: command not found" >&2
return 127
fi
local cmd=${1#Z}
case "$(type -t "$cmd")" in
builtin|keyword) help "$cmd" ;;
file) man "$cmd" ;;
alias) alias "$cmd" ;;
function) type "$cmd" ;;
*) echo "$cmd: command not found" >&2; return 127 ;;
esac
}
Related
When I input this command in zsh:
which conda
It returns
conda () {
\local cmd="${1-__missing__}"
case "$cmd" in
(activate | deactivate) __conda_activate "$#" ;;
(install | update | upgrade | remove | uninstall) __conda_exe "$#" || \return
__conda_reactivate ;;
(*) __conda_exe "$#" ;;
esac
}
But I hope it returns the absolute path as it behaves in bash.
When I input:
type conda
It returns
conda is a shell function from /Users/qxchen/.zshrc
Actually, there is no function in .zshrc named by conda
I delete the script in .zshrc which is made by "conda init zsh", and then I add the absolute path of miniconda/bin to PATH.
But in bash, "which conda" returns the absolute path of "conda".
/Users/ABC/miniforge3/condabin/conda
And the result of "type conda":
conda is a function
conda ()
{
\local cmd="${1-__missing__}";
case "$cmd" in
activate | deactivate)
__conda_activate "$#"
;;
install | update | upgrade | remove | uninstall)
__conda_exe "$#" || \return;
__conda_reactivate
;;
*)
__conda_exe "$#"
;;
esac
}
I want zsh to behave like bash at this point, aka "which conda" should return the path of conda, and "type conda" should return its real type.
What should I do?
Thanks for your help in advance.
I have written a ZSH function whose output is a command line which runs a program I need the user to be able to interact with.
At the moment I just echo the command line and instruct the user to copy-paste it so that they have the necessary access to its pipes, however is there a way I can just have the function finish by entering the command for the user as if they had copied and pasted it themselves?
I have looked into using zle but that seems to require a key binding, whereas I just want the user to be able to run: myzshfunction arg1 and the ultimate result to be their terminal attached to the program launched as a result of some processing of their arg1.
$ myzshfunction arg2*2
Run this command! foobar baz4
$ foobar baz4
...
The function looks something like this:
myzshfunction() {
if [[ $# = 0 ]]
then
echo "usage: myzshfunction 1.2.3.4"
return
fi
local creds=`curl "https://xxx/$1/latest" | jq -r 'x'`
local cred_arr=("${(#s|/|)creds}")
local pwd_pipe=$(mktemp -u)
mkfifo $pwd_pipe
exec 3<>$pwd_pipe
rm $pwd_pipe
echo $cred_arr[2] >&3
echo "Run this: sshpass -d3 ssh -o StrictHostKeyChecking=no -o UserKnownHostsFile=/dev/null "$cred_arr[1]#$1"
exec 3>&-
}
TIA
Use print -z to add text to the buffer. From the documentation:
-z Push the arguments onto the editing buffer stack, separated by spaces.
Calling foo, defined below, will result in hi being placed on the command line as if the user had typed it. For example,
% foo () { print -z hi; }
% foo
% hi
The best solution I could come up with was to use zle - the Zsh Line Editor.
This lets you update the command the user is currently editing, which to me feels a bit hacky. I would prefer a solution that lets you call a function, hit return, and then cleanly run a function with STDIO attached to your terminal as if you had run the resulting command line.
Perhaps you could emulate this by bindkey'ing the return key and doing some sort of decision/routing from there to see if the user wants to call myfunc. For now, my solution requires the Esc+i sequence is entered after typing a target for $host.
zle-myfunc() {
apikey=$(keychain-environment-variable api-key)
if [ $? -ne 0 ]; then
echo "Add your api-key to the keychain: "
BUFFER='security add-generic-password -U -a ${USER} -D "environment variable" -s "api-key" -w'
zle accept-line
return 1
fi
local host=$BUFFER
zle kill-buffer
local creds=`curl ..." | jq -r ...`
if [ -z creds ]; then
echo "Couldn't get creds, check your network"
return 1
fi
local creds_arr=("${(#s|/|)creds}")
local pwd_pipe=$(mktemp -u)
mkfifo $pwd_pipe
exec 3<>$pwd_pipe
# anonymise the pipe
rm $pwd_pipe
echo "$creds_arr[2]" >&3
BUFFER="sshpass -d3 ssh -o StrictHostKeyChecking=no -o UserKnownHostsFile=/dev/null $creds_arr[1]#$host"
zle accept-line
# exec 3>&-
}
zle -N zle-myfunc
bindkey '\ei' zle-myfunc
I have a script that takes file like arguments (multi part arguments), I am fetching the possible values and putting them in an array called raw and then using
_multi_parts / "(${raw[#]})"
to autocomplete. The problem is that this is case sensitive, how can I make it so that it I type mycommand get fo and press Tab it will autocomplete to mycommand get Foo/ if Foo is one of the things in raw.
The full completion is here for reference:
_mycommand() {
local curcontext="$curcontext" state line
_arguments "1: :->command" "*: :->label"
case $state in
command)
_arguments "1: :(add get ls rm)"
;;
*)
case $words[2] in
add|get|ls|rm)
if [ -f ~/.pts ]; then
IFS=$'\n' read -d '' -r raw <<< "$(mycommand ls)"
_multi_parts / "(${raw[#]})"
fi
;;
*)
_files
;;
esac
esac
}
_mycommand "$#"
mycommand ls outputs path like names like the following:
Foo/Bar/x
Foo/Bar/y
Derp/z
Placeholder/z
Okay I figured it out:
Change lines
IFS=$'\n' read -d '' -r raw <<< "$(mycommand ls)"
_multi_parts / "(${raw[#]})"
To
IFS=$'\n' raw=($(mycommand ls))
_multi_parts -M "m:{[:lower:][:upper:]}={[:upper:][:lower:]}" / raw
I'm wrote a function called test_status that I am trying to incorporate in my tmux status bar. To give some background, my tests will output to a file called .guard_result with either success or failure and the test_status function reads from that file and echoes a 💚 if my tests are passing and a ❤️ if they are failing.
The good news is running test_status works just fine, I'm just having trouble getting it to work with tmux. What am I missing here?
# ~/.oh-my-zsh/custom/aliases.zsh
function test_status {
if [ ! -f "./.guard_result" ]; then
echo "?"
return 1
fi
result="$(cat ./.guard_result)"
if [[ $result == *"success"* ]]
then
echo "💚";
elif [[ $result == *"fail"* ]]
then
echo "❤️";
fi
}
This function works... Here is Tmux configuration (which doesn't show result):
# ~/.tmux.conf
set -g status-right "#(test_status) #[fg=colour245]%d %b %Y #[fg=white]:: #[fg=colour245]%l:%M %p"
I know I must be missing something simple... Thanks for your help!
tmux passes shell commands to /bin/sh not zsh. And even if tmux would use zsh, the function would not be available in that context as ~/.zshrc, which loads oh-my-zsh, is only read for interactive shells.
In order to get the the output of test_status into tmux, I would suggest to put the function into a zsh script and call that.
You can either source ~/.oh-my-zsh/custom/aliases.zsh from within the script and then call test_status:
#!/usr/bin/zsh
# ^ make sure this reflects the path to zsh (`type zsh`)
source ~/.oh-my-zsh/custom/aliases.zsh
test_status
Or you can just put the entire function into the script, so as to not clutter alias.zsh:
#!/usr/bin/zsh
function test_status {
if [ ! -f "./.guard_result" ]; then
echo "?"
return 1
fi
result="$(cat ./.guard_result)"
if [[ $result == *"success"* ]]
then
echo "💚";
elif [[ $result == *"fail"* ]]
then
echo "❤️";
fi
}
Safe the script somewhere (e.g. /path/to/test_status.zsh), make it executable (chmod a+x /path/to/test_status.zsh) and call it by path in the tmux configuration.
I want to be able to tell if a command exists on any POSIX system from a shell script.
On Linux, I can do the following:
if which <command>; then
...snip...
fi
However, Solaris and MacOS which do not give an exit failure code when the command does not exist, they just print an error message to STDOUT.
Also, I recently discovered that the which command itself is not POSIX (see http://pubs.opengroup.org/onlinepubs/9699919799/idx/utilities.html)
Any ideas?
command -v is a POSIX specified command that does what which does.
It is defined to to return >0 when the command is not found or an error occurs.
You could read the stdout/stderr of "which" into a variable or an array (using backticks) rather than checking for an exit code.
If the system does not have a "which" or "where" command, you could also grab the contents of the $PATH variable, then loop over all the directories and search for the given executable. That's essentially what which does (although it might use some caching/optimization of $PATH results).
One which utility is available as shell script in the Git repository of debianutils package of Debian Linux. The script seems to be POSIX compatible and you could use it, if you take into account copyright and license. Note that there have been some controversy whether or not and how the which utility should be deprecated; (at time of writing) current version in Git shows deprecation message whereas an earlier version added later removed -s option to enable silent operation.
command -v as such is problematic as it may output a shell function name, an alias definition, a keyword, a builtin or a non-executable file path. On the other hand some path(s) output by which would not be executed by shell if you run the respective argument as such or as an argument for command. As an alternative for using the which script, a POSIX shell function using command -v could be something like
#!/bin/sh
# Argument $1 should be the basename of the command to be searched for.
# Outputs the absolute path of the command with that name found first in
# a directory listed in PATH environment variable, if the name is not
# shadowed by a special built-in utility, a regular built-in utility not
# associated with a PATH search, or a shell reserved word; otherwise
# outputs nothing and returns 1. If this function prints something for
# an argument, it is the path of the same executable as what 'command'
# would execute for the same argument.
executable() {
if cmd=$(unset -f -- "$1"; command -v -- "$1") \
&& [ -z "${cmd##/*}" ] && [ -x "$cmd" ]; then
printf '%s\n' "$cmd"
else
return 1
fi
}
Disclaimer: Note that the script using command -v above does not find an executable whose name equals a name of a special built-in utility, a regular built-in utility not associated with a PATH search, or a shell reserved word. It might not find an executable either in case if there is non-executable file and executable file available in PATH search.
A function_command_exists for checking if a command exists:
#!/bin/sh
set -eu
function_command_exists() {
local command="$1"
local IFS=":" # paths are delimited with a colon in $PATH
# iterate over dir paths having executables
for search_dir in $PATH
do
# seek only in dir (excluding subdirs) for a file with an exact (case sensitive) name
found_path="$(find "$search_dir" -maxdepth 1 -name "$command" -type f 2>/dev/null)"
# (positive) if a path to a command was found and it was executable
test -n "$found_path" && \
test -x "$found_path" && \
return 0
done
# (negative) if a path to an executable of a command was not found
return 1
}
# example usage
echo "example 1";
command="ls"
if function_command_exists "$command"; then
echo "Command: "\'$command\'" exists"
else
echo "Command: "\'$command\'" does not exist"
fi
command="notpresent"
if function_command_exists "$command"; then
echo "Command: "\'$command\'" exists"
else
echo "Command: "\'$command\'" does not exist"
fi
echo "example 2";
command="ls"
function_command_exists "$command" && echo "Command: "\'$command\'" exists"
command="notpresent"
function_command_exists "$command" && echo "Command: "\'$command\'" does not exist"
echo "End of the script"
output:
example 1
Command: 'ls' exists
Command: 'notpresent' does not exist
example 2
Command: 'ls' exists
End of the script
Note that even the set -eu that turns -e option for the script was used the script was executed to the last line "End of the script"
There is no Command: 'notpresent' does not exist in the example 2 because of the && operator so the execution of echo "Command: "\'$command\'" does not exist" is skipped but the execution of the script continues till the end.
Note that the function_command_exists does not check if you have a right to execute the command. This needs to be done separately.
Solution with command -v <command-to-check>
#!/bin/sh
set -eu;
# check if a command exists (Yes)
command -v echo > /dev/null && status="$?" || status="$?"
if [ "${status}" = 127 ]; then
echo "<handle not found 1>"
fi
# check if a command exists (No)
command -v command-that-does-not-exists > /dev/null && status="$?" || status="$?"
if [ "${status}" = 127 ]; then
echo "<handle not found 2>"
fi
produces:
<handle not found 2>
because echo was found at the first example.
Solution with running a command and handling errors including command not found.
#!/bin/sh
set -eu;
# check if a command exists (No)
command -v command-that-does-not-exist > /dev/null && status="$?" || status="$?"
if [ "${status}" = 127 ]; then
echo "<handle not found 2>"
fi
# run command and handle errors (no problem expected, echo exist)
echo "three" && status="$?" || status="$?"
if [ "${status}" = 127 ]; then
echo "<handle not found 3>"
elif [ "${status}" -ne 0 ]; then
echo "<handle other error 3>"
fi
# run command and handle errors (<handle not found 4> expected)
command-that-does-not-exist && status="$?" || status="$?"
if [ "${status}" = 127 ]; then
echo "<handle not found 4>"
elif [ "${status}" -ne 0 ]; then
echo "<handle other error 4>"
fi
# run command and handle errors (command exists but <handle other error 5> expected)
ls non-existing-path && status="$?" || status="$?"
if [ "${status}" = 127 ]; then
echo "<handle not found 5>"
elif [ "${status}" -ne 0 ]; then
echo "<handle other error 5>"
fi
produces:
<handle not found 2>
three
./function_command_exists.sh: 34: ./function_command_exists.sh: command-that-does-not-exist: not found
<handle not found 4>
ls: cannot access 'non-existing-path': No such file or directory
<handle other error 5>
The following works in both bash and zsh and avoids both functions and aliases.
It returns 1 if the binary is not found.
bin_path () {
if [[ -n ${ZSH_VERSION:-} ]]; then
builtin whence -cp "$1" 2> /dev/null
else
builtin type -P "$1"
fi
}