PowerShell vs Bash Compared (PowerShell for Unixers)

This pages shows the equivalent of PowerShell for common unix commands related to text processing, such as {grep, head, find, sort, uniq, wc, …}. The version of unix tool used here are Bash and GNU. (that's most linuxes, but not BSDs, Solaris, Mac OS X.)

For simpler things such as {cd, mkdir, ls, …}, see PowerShell as Bash.

cat ‹file name› | where { $_ -match "‹regex pattern›"}

cat ‹file name› | %{$_ -replace "‹regex pattern›","‹replace string›"}

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, shew 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". 

Detail

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)

See also a short intro to PowerShell for unixers:

• PowerShell for Unix Hackers - Part I By Rob Shinn. @ docs.google.com…