Why am I getting gibberish result in Windows terminal?

Question

I am trying to compare version in windows terminal. It works great in Git Bash but in Windows terminal it shows gibberish and wrong result?

verlte() {
    [  "$1" = "`echo -e "$1\n$2" | sort -V | head -n1`" ]
}

verlt() {
    [ "$1" = "$2" ] && return 1 || verlte $1 $2
}

verlte 2.5.7 2.5.6 && echo "yes" || echo "no" # no
verlt 2.4.10 2.4.9 && echo "yes" || echo "no" # no
verlt 2.4.8 2.4.10 && echo "yes" || echo "no" # yes
verlte 2.5.6 2.5.6 && echo "yes" || echo "no" # yes
verlt 2.5.6 2.5.6 && echo "yes" || echo "no" # no

Result in Windows terminal

Result in Git Bash

`[` is a POSIX command but it's part of the `[]` operator in powershell — phuclv, Apr 21 '22 at 06:45
@phuclv thanks, can the script changed make it work on windows? I have tried but didn't work. — i_am_learning, Apr 21 '22 at 07:06
of course you can, but you need to use the shell's syntax. Bash, ksh, csh, zsh, cmd, powershell... all have different syntaxes and you can't use bash syntax on another shell — phuclv, Apr 21 '22 at 09:34

score 1 · Answer 1 · answered Apr 21 '22 at 19:51

Borrowing from Sort a list that contains version numbers properly, which references How to sort by file name the same way Windows Explorer does?, here's my attempt at converting to PowerShell syntax:

# compare two arbitrary version strings using natural sorting
# allows strings to contain non-numeric components
function verlte {
    param(
        [string]$v1,
        [string]$v2
    )

    function ToNatural {
        param( [string]$v )
        [regex]::Replace($v, '\d+', { $args[0].Value.PadLeft(20) })
    }
    
    (ToNatural $v1) -le (ToNatural $v2)
}

function verlt {
    param(
        [string]$v1,
        [string]$v2
    )

    if ($v1 -eq $v2) { return $false }
    verlte $v1 $v2
}

verlte 2.5.7 2.5.6 # False
verlt 2.4.10 2.4.9 # False
verlt 2.4.8 2.4.10 # True
verlte 2.5.6 2.5.6 # True
verlt 2.5.6 2.5.6 # False

for comparing file names you need to use natural sort but specifically for versions you don't actually need that — phuclv, Apr 22 '22 at 01:27
My goal was to replicate the behavior of GNU `sort -V`, which uses a [natural sort](https://www.gnu.org/software/coreutils/manual/html_node/Version-sort-and-natural-sort.html), i.e. allowing arbitrary non-numeric text in the input string. I wanted to replicate the behavior in the code provided provided by [i_am_learning](https://stackoverflow.com/users/17533344/i-am-learning) — Slartiprefect, Apr 22 '22 at 13:05

phuclv · Accepted Answer · 2022-04-22T14:55:28.843

It seems you're comparing versions. In PowerShell and .NET framework there are already [version] to do that:

PS C:\Users> [version]"2.5.7" -le [version]"2.5.6"
False
PS C:\Users> [version]"2.4.10" -lt [version]"2.4.9"
False
PS C:\Users> [version]::new(2, 4, 8) -lt [version]::new(2, 4, 10)
True
PS C:\Users> [version]"2.5.6" -le [version]"2.5.6"
True
PS C:\Users> [version]::new(2, 5, 6) -lt [version]::new(2, 5, 6)
False

See PowerShell Comparison Operators for more information

Note that Windows Terminal is a terminal and can't run anything. Same to other terminals like conhost (the default terminal on older Windows), term, xterm, iterm, konsole... The thing that runs commands is called the shell and a shell must be connected to some terminal to work. So saying "running in Windows Terminal" makes almost no sense because the error comes from the shell. Your command is a bash command so obviously if you run bash in Windows Terminal then it'll run properly. It's unclear which shell you're using but

In PowerShell [ "$1" = "`echo -e "$1\n$2" | sort -V | head -n1`" ] completely fails to parse because in PowerShell ` is an escape character (which means your command doesn't terminate), and =, [/] in PowerShell are an operator instead of a normal character like in bash
In cmd $ isn't the character for variable and argument substitution, and ` also has no special meaning, so if there's a [.exe in your path then cmd will pass the whole literal command to the [ command which will fail to compare anything

Each shell has its own syntax, don't try to run commands written for a shell on another completely different one

Why am I getting gibberish result in Windows terminal?

2 Answers2