PowerShell vs Bash

This pages shows the equivalent of PowerShell for common unix commands related to text processing.

Simple Commands

The following bash commands have PowerShell alias. (but the options may not be the same)

1. cd
2. pwd
3. ls
4. pushd
5. popd
6. cp
7. rm
8. rmdir
9. mv
10. cat
11. echo
12. set
13. ps
14. kill
15. clear
16. man

file content

Purpose	Bash + GNU utils	PowerShell
create new file	touch ff	ni ff -type file ni ↔ New-Item
show file content	cat ff	cat ff cat ↔ Get-Content ↔ gc
merge file	cat f1 f2 > new.txt	cat f1, f2 > new.txt
show first n lines	head -n 50 ff	cat ff | select -first 50
show last n lines	tail	cat file | select -last 50

find file

Purpose	Bash + GNU utils	PowerShell
list dirs	find . -type d	gci . -Recurse -name gci ↔ Get-ChildItem
list files	find . -type f	?
list html files	find . -name "*html"	gci . -Recurse -name -include *html
list empty files	find . -size 0	ls . -recurse | where {$_.length -eq 0}
delete empty files	find . -type f -size 0 -exec rm {} \;	?

search text (grep)

Purpose	Bash + GNU utils	PowerShell
search text	grep xyz f.txt	select-string f.txt -pattern xyz -CaseSensitive
search text	grep xyz *html	select-string *html -pattern xyz -CaseSensitive
search text	grep -i	select-string without -CaseSensitive
search text	grep --invert-match	select-string with -NotMatch
search text	grep --files-with-matches	◇

cat file_name | where { $_ -match "regex_pattern"}

cat file_name | %{$_ -replace "regex_pattern","replace_string"}

diff, sort, get column etc

Purpose	Bash + GNU utils	PowerShell
◇	cmp	diff diff ↔ compare ↔ Compare-Object
compare file difference	diff f1 f2	diff (cat f1) (cat f2)
◇	sed	?
print nth column	awk '{print $12 , $7}'	?
◇	sort	sort (Sort-Object)
◇	uniq	sort -Unique
◇	wc	Measure-Object (measure ↔ Measure-Object)
◇	tr	◇
◇	basename	◇
◇	dirname	◇

Work In Progress

Note: this page is a mess. It's work in progress. (started when i wished to convert my log processing bash script to PowerShell)

todo, show PowerShell equivalent of this:

find . -print0 | xargs -0 -l -i echo "{}";
find . -name "*bmp" -print0 | xargs -0 -l -i basename -s ".bmp" "{}" | xargs -0 -l -i convert "{}.bmp" "{}.png". 

touch

# creating a new file in current dir
touch myfile.txt

# creating a new file in current dir
new-item -name myfile.txt -type "file"

Redirect “>”

# put content in a file
echo "some" > myfile.txt
echo "some more" >> myfile.txt # append

# put content in a file
"some" > myfile.txt
"some more" >> myfile.txt # append

Note that, by default, the PowerShell redirect operator ">" creates files with little endian utf-16 encoding, and lines are hard-wrapped at 80 chars, and line ending uses Windows convension of "\r\n" (ascii 13 and 10).

On unixes, the conventional file encoding is utf-8, and lines are not hard-wrapped (sometimes truncated (deleted) silently), and line ending uses "\n" (ascii 10).

To create unix style output, use out-file, like this:

"1'n2'n3" | out-file -Encoding utf8 -width 999000 myfile.txt

However, the line ending used is still "\r\n". To create unix line ending of just "\n", use:

… | Out-String | %{ $_.Replace("`r`n","`n") } | out-file …

However, the end of the file will still contain a "\r".

cat

Unix “cat” can be used to read a file, or join several files. PowerShell equivalent is “get-content” with alias “cat” too.

# display a file content. (cat is alias of get-content)
cat myfile.txt

Note that by default, PowerShell assumes ascii. You can set your $OutputEncoding like this:

# set $OutputEncoding to utf-8
$OutputEncoding = New-Object -typename System.Text.UTF8Encoding

---

Thanks to Shivashis Saha for addition on “cat”. He also sends the following:

split

For example, if you want to split a line based on “:”, you can use the following line:

(given $str is a line with different fields separated by ":")
$temp=@($str -split ":"); 

Super thanks to Jeffrey Snover of Microsoft for helping on about 10 of the items. (Jeffrey's the inventor of PowerShell)