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On Linux, only the `help` function respects the `PAGER` env var.
Prerequisites
- [x] Write a descriptive title.
- [x] Make sure you are able to repro it on the latest released version
- [x] Search the existing issues.
- [x] Refer to the FAQ.
- [x] Refer to Differences between Windows PowerShell 5.1 and PowerShell.
Steps to reproduce
I think ideally, Out-Host -Paging should use the same logic as the help function.
For what it's worth, I think the help implementation has the correct logic:
`help` implementation
PS> (Get-Command help).Definition
{
# By default use more on Windows and less on Linux.
$pagerCommand = 'less'
$pagerArgs = '-s','-P','Page %db?B of %D:.\. Press h for help or q to quit\.'
# Respect PAGER environment variable which allows user to specify a custom pager.
# Ignore a pure whitespace PAGER value as that would cause the tokenizer to return 0 tokens.
if (![string]::IsNullOrWhitespace($env:PAGER)) {
if (Get-Command $env:PAGER -ErrorAction Ignore) {
# Entire PAGER value corresponds to a single command.
$pagerCommand = $env:PAGER
$pagerArgs = $null
}
else {
# PAGER value is not a valid command, check if PAGER command and arguments have been specified.
# Tokenize the specified $env:PAGER value. Ignore tokenizing errors since any errors may be valid
# argument syntax for the paging utility.
$errs = $null
$tokens = [System.Management.Automation.PSParser]::Tokenize($env:PAGER, [ref]$errs)
$customPagerCommand = $tokens[0].Content
if (!(Get-Command $customPagerCommand -ErrorAction Ignore)) {
# Custom pager command is invalid, issue a warning.
Write-Warning "Custom-paging utility command not found. Ignoring command specified in `$env:PAGER: $env:PAGER"
}
else {
# This approach will preserve all the pagers args.
$pagerCommand = $customPagerCommand
$pagerArgs = if ($tokens.Count -gt 1) {$env:PAGER.Substring($tokens[1].Start)} else {$null}
}
}
}
$pagerCommandInfo = Get-Command -Name $pagerCommand -ErrorAction Ignore
if ($pagerCommandInfo -eq $null) {
$help
}
elseif ($pagerCommandInfo.CommandType -eq 'Application') {
# If the pager is an application, format the output width before sending to the app.
$consoleWidth = [System.Math]::Max([System.Console]::WindowWidth, 20)
if ($pagerArgs) {
$help | Out-String -Stream -Width ($consoleWidth - 1) | & $pagerCommand $pagerArgs
}
else {
$help | Out-String -Stream -Width ($consoleWidth - 1) | & $pagerCommand
}
}
else {
# The pager command is a PowerShell function, script or alias, so pipe directly into it.
$help | & $pagerCommand $pagerArgs
}
}
Expected behavior
$ PAGER='bat --paging=always' pwsh # or any other custom pager
PS> help help
# output using the bat pager
<CTRL-D>
$ PAGER='bat --paging=always' pwsh
PS> Get-Process | Out-Host -Paging
# output using the bat pager
# Note how 'more' and 'less' are hardcoded applications. This might be fine
# actually
PS> (Get-Command more).Definition
/usr/bin/more
PS> (Get-Command less).Definition
/usr/bin/less
Actual behavior
$ PAGER='bat --paging=always' pwsh # or any other custom pager
PS> help help
# output using the bat pager
<CTRL-D>
$ PAGER='bat --paging=always' pwsh
PS> Get-Process | Out-Host -Paging
# The main pager always use 'more' no matter what (!!)
# output using 'more' pager
# Note how 'more' and 'less' are hardcoded applications. This might be fine
# actually
PS> (Get-Command more).Definition
/usr/bin/more
PS> (Get-Command less).Definition
/usr/bin/less
Error details
Environment data
Name Value
---- -----
PSVersion 7.5.4
PSEdition Core
GitCommitId 7.5.4-0-g7c8d9e7e0ed2fc1f2caf50746fe9fef720ca2a0a
OS Arch Linux
Platform Unix
PSCompatibleVersions {1.0, 2.0, 3.0, 4.0…}
PSRemotingProtocolVersion 2.3
SerializationVersion 1.1.0.1
WSManStackVersion 3.0
Visuals
No response
I think it should respect $env:PAGER if it's defined. If it's not defined, it should work as it does now:
Using Paging is similar to using the more command.
I think it should respect $env:PAGER if it's defined. If it's not defined, it should work as it does now
I agree. For what it's worth, I think the help implementation has the correct logic:
`help` implementation
PS> (Get-Command help).Definition
{
# By default use more on Windows and less on Linux.
$pagerCommand = 'less'
$pagerArgs = '-s','-P','Page %db?B of %D:.\. Press h for help or q to quit\.'
# Respect PAGER environment variable which allows user to specify a custom pager.
# Ignore a pure whitespace PAGER value as that would cause the tokenizer to return 0 tokens.
if (![string]::IsNullOrWhitespace($env:PAGER)) {
if (Get-Command $env:PAGER -ErrorAction Ignore) {
# Entire PAGER value corresponds to a single command.
$pagerCommand = $env:PAGER
$pagerArgs = $null
}
else {
# PAGER value is not a valid command, check if PAGER command and arguments have been specified.
# Tokenize the specified $env:PAGER value. Ignore tokenizing errors since any errors may be valid
# argument syntax for the paging utility.
$errs = $null
$tokens = [System.Management.Automation.PSParser]::Tokenize($env:PAGER, [ref]$errs)
$customPagerCommand = $tokens[0].Content
if (!(Get-Command $customPagerCommand -ErrorAction Ignore)) {
# Custom pager command is invalid, issue a warning.
Write-Warning "Custom-paging utility command not found. Ignoring command specified in `$env:PAGER: $env:PAGER"
}
else {
# This approach will preserve all the pagers args.
$pagerCommand = $customPagerCommand
$pagerArgs = if ($tokens.Count -gt 1) {$env:PAGER.Substring($tokens[1].Start)} else {$null}
}
}
}
$pagerCommandInfo = Get-Command -Name $pagerCommand -ErrorAction Ignore
if ($pagerCommandInfo -eq $null) {
$help
}
elseif ($pagerCommandInfo.CommandType -eq 'Application') {
# If the pager is an application, format the output width before sending to the app.
$consoleWidth = [System.Math]::Max([System.Console]::WindowWidth, 20)
if ($pagerArgs) {
$help | Out-String -Stream -Width ($consoleWidth - 1) | & $pagerCommand $pagerArgs
}
else {
$help | Out-String -Stream -Width ($consoleWidth - 1) | & $pagerCommand
}
}
else {
# The pager command is a PowerShell function, script or alias, so pipe directly into it.
$help | & $pagerCommand $pagerArgs
}
}
The WG discussed this. We agree that when -paging is used with Out-Host, it should respect use of $env:PAGER if it's defined. This should be true for both Windows and non-Windows.
