I accidentally wrote ls' instead of ls for listing the files. And it shows the > option. later I checked with other commands like cd', all providing >. What this command is for?
Example:
user:~$ ls'
>
>
>
user:~$ cd'
>
>
You have started a string parameter after command. For example, you can pass multiline parameter this way. All typed data between '' will be treated as one parameter.
Related
I try certain source codes using PowerShell to extract an password protected archive using 7zip:
This command doesn' work (7zip is an alias for $7zipPath):
& 7zip x "$zipFile" -o "$output" -p $zipFilePassword
I get the this error:
Command Line Error:
Too short switch:
But when I remove the spaces between the variables -o and -p, the archive can be extracted. This behaviour confuses me with other command line tools like git etc.? Why is it so?
The behavior is specific to 7-Zip (7z.exe) and applies to whatever program (shell) you invoke it from:
Deviating from widely used conventions observed by CLIs such as git, 7z requires that even switches (options) that have mandatory arguments, such as -o and -p, have the argument directly attached to the switch name - no spaces are allowed:
& 7zip x $zipFile -o"$output" -p"$zipFilePassword"
Note that you normally need not enclose variable references in PowerShell in "..." (note how $zipFile isn't), even if they contain spaces. However, in order to attach them directly to switch names, you do.
Alternatively, you could enclose the entire token - switch name and argument - in double quotes:
& 7zip x $zipFile "-o$output" "-p$zipFilePassword"
I'm using sh as my shell on FreeBSD but I want to be able to have a pretty prompt like the one bash gives me on Ubuntu. There are two things that the FreeBSD implementation of sh seems to lack as far as PS1 escape characters go:
The \w works but does not expand $HOME to ~, so this is something I have already hacked up myself
I can use PS1 to update the prompt on the terminal, but as far as I can tell it is not possible to use the PS1 variable to update the title bar as well. ESC and BEL fail to set the title as one would expect if they were using bash or ksh
Here is my .shrc file
update_prompt() {
case "$PWD" in
"$HOME"*)
pretty_pwd="~${PWD#*"${HOME}"}"
;;
"/usr$HOME"*)
pretty_pwd="~${PWD#*"/usr${HOME}"}"
;;
*)
pretty_pwd="$PWD"
;;
esac
case "$TERM" in
xterm*|rxvt*)
PS1="[$USER#\\h $pretty_pwd]\\$ "
;;
*)
;;
esac
printf "\\033]0;[%s#$(hostname -s): %s]\\007" "$USER" "$pretty_pwd"
}
update_prompt
So when I fire up a terminal or log in via ssh, it gives the pretty prompt that I like. But now I need this function to run every time that cd is executed and returns an exit status of 0.
I was going to use an alias that was something like:
alias cd="cd $1 && update_prompt"
but that was before I realized that aliases do not except arguments. How might I go about doing something like this?
You can use a function instead of an alias:
cd() {
command cd "$#" && update_prompt
}
Just put it into ~/.shrc. You have to use command here to let sh know that you are referring to the actual cd builtin command instead of the function you've just defined.
Refer to the sh(1) manual page for the details on how to make sh(1) source the ~/.shrc file when it starts:
Therefore, a user should place commands that are to be executed only at login
time in the .profile file, and commands that are executed for every shell
inside the ENV file. The user can set the ENV variable to some file by placing
the following line in the file .profile in the home directory, substituting for
.shrc the filename desired:
ENV=$HOME/.shrc; export ENV
I use this trick in my cd alias manager. Here's a link to the source code of the function: https://github.com/0mp/goat/blob/v2.5.0/libgoat.sh#L31-L57
You can do it with alias+arguments if you swap the commands:
$ alias cd="echo change; cd"
$ pwd
/nas
$ cd /
change
$ pwd
/
$ cd /etc
change
$ pwd
/etc
$
Is there a way to add aliases to the bash terminal when using it from within Visual Studio Code?
I found the answer here
https://gist.github.com/wzup/36b5159d8c580b827384
Take as an inspiration
# create a file C:\Users\[user]\.bashrc
# add this content
# add your onw aliases or changes these ones as you like
# to make a dot (.bashrs) file in windows, create a file ".bashrs." (without extention) and save. windows will save it as ".bashrc"
alias ls='ls -alh'
alias cdnginx='cd /c/nginx && ls'
alias cdmcga='cd /c/Users/[user]/sbox/node/mcga && ls'
alias cdfood9='cd /c/Users/[user]/sbox/node/food9 && ls'
alias cdmysql='cd /c/nginx/mysql/bin && ls'
alias cdsbox='cd /c/Users/[user]/sbox && ls'
alias cdangular='cd /c/Users/[user]/sbox/angularjs && ls'
alias cdmongobin='cd "/c/Program Files/MongoDB/Server/3.0/bin" && ls'
alias cdmongodata='cd /c/mongodb/data/db && ls'
alias sbrc='cd ~ && source .bashrc'
alias mydocs='cd ~/Documents'
I am using MAC with zsh, and is same place (your user folder) and the file has the name .zshrc
For see the hidden files in MAC: Cmd + shift + .
alias ball="npm run build-all"
In bash shell scripting, I would typically run :> file to empty a file.
Now using fish, things are slightly different and the above command doesn't work.
What is fish equivalent?
Although it's not as short as :, true is a command that will work everywhere and produces no output:
true > file
Probably the easiest way that will be work in both Fish and Bash is to do echo "" > file
EDIT: Commenter was absolutely right echo "" > file produces a file with a newline, the correct command I was thinking of to create an empty file is cat /dev/null > file.
There is, and always was the magic method called touch which set change time to actual or create non-existent file. For compatiblity I suggest you to use this way in all scripts that you write (even if you write bash code).
I'm trying to execute the command below in a PowerShell script
C:\PATH TO GPG\gpg.exe --output OUTPUTFILE.csv --batch --passphrase-fd 0 --decrypt C:\PATH TO INPUT\INPUTFILE.txt < C:\PATH TO PASS\Passphrase.txt
When I assign various sections of the command to variables and then combine them in a command varible and try and execute it as follows:
$decryptCommand = "${gpg} --output ${dateStamp}.csv --batch --passphrase-fd 0 --decrypt ${fileName} < ${passphraseFile}"
&$decryptCommand
I receive the following error:
The term 'XXXX' is not recognized as the name of a cmdlet, function, script file, or operable program. Check the spelling of the name, or if a path was included, verify that the path is correct and try again.
I have tried to surround various parts of the command in single and double quotes but nothing I've tried seems to work.
Is there something extra I should be doing to execute this command from a PowerShell script?
There are several problems with you script. First, you don't need to surround variable with {}, secon - you have to pass parameters seperately, like this:
&$gpg --output $dateStamp.csv --batch --passphrase-fd 0 --decrypt $fileName < $passphraseFile
The only thing I'm not sure about is < symbol. It might be the case that you will need to escape it with '