Write a script that can run in Bash / shell and PowerShell

Mission ： Create an integration script to set some environment variables , Use wget Download the file and run it .

The challenge is that it needs to be able to Windows PowerShell and bash / shell Running on SAME Script .

This is a shell Script ：

#!/bin/bash
# download a script
wget http://www.example.org/my.script -O my.script
# set a couple of environment variables
export script_source=http://www.example.org
export some_value=floob
# Now execute the downloaded script
bash ./my.script

This is related to PowerShell The situation is the same in ：

wget http://www.example.org/my.script -O my.script.ps1
$env:script_source="http://www.example.org"
$env:some_value="floob"
PowerShell -file ./my.script.ps1

So I want to know whether these two scripts can be merged and run successfully on either platform ？

I've been trying to find a way to put them in the same script , And let bash and PowerShell.exe Ignore mistakes , But it didn't work .

I don't know how compatible this is , but PowerShell Treat the string as text and finally display it on the screen , Bash Think of them as commands and try to run them , And both support the same function definition syntax . therefore , Put the function name in quotation marks , Only Bash Will run it , take “exit” Put it in quotation marks , Only Bash You're going to quit . Then write PowerShell Code .

NB. It works , Because the two one. shell Syntax overlap in , And your script is simple – Run commands and process variables . If you try to use more advanced scripts (if / then,for,switch,case etc. ) For any language , Another possibility is to complain .

Save it as dual.ps1, In order to PowerShell Be satisfied with it , chmod x dual.ps1 therefore Bash Will run it

#!/bin/bash
 
function dobashThings {
    
    wget http://www.example.org/my.script -O my.script
    # set a couple of environment variables
    export script_source=http://www.example.org
    export some_value=floob
    # Now execute the downloaded script
    bash ./my.script
}
 
"dobashThings"  # This runs the bash script,in PS it's just a string
"exit"          # This quits the bash version,in PS it's just a string
 
 
# PowerShell code here
# --------------------
Invoke-WebRequest "http://www.example.org/my.script.ps1" -Outfile my.script.ps1
$env:script_source="http://www.example.org"
$env:some_value="floob"
PowerShell -file ./my.script.ps1

then

./dual.ps1

Edit on any system ： You can include more complex code by annotating code blocks with different prefixes , Then let each language filter out its own code and evaluate it ( The usual safety warnings apply to eval), for example ： In this way ( Included in the Harry Johnston The advice of )：

#!/bin/bash
 
#posh $num = 200
#posh if (150 -lt $num) {
    
#posh write-host "PowerShell here"
#posh }
 
#bash thing="xyz"
#bash if [ "$thing" = "xyz" ]
#bash then
#bash echo "Bash here"
#bash fi
 
function RunBashStuff {
    
    eval "$(grep '^#bash' $0 | sed -e 's/^#bash //')"
}
 
"RunBashStuff"
"exit"
 
((Get-Content $MyInvocation.MyCommand.source) -match '^#posh' -replace '^#posh ') -join "`n" | Invoke-Expression