一个转换图片格式的script

也是在monad的 team blog上看到的

原code 如下

# Convert one graphic image to another

param ( $inFile, $type = "gif", $outFile, [switch]$force )

# First check to see if our input file exists

$iFile = (resolve-path $inFile -ea silentlycontinue ).path

if ( ! $iFile ) { "File \'$inFile\' not found, exiting" ; exit }

# now check to see if the output file exists, if force

# we will continue, otherwise we exit

if ( ! $outFile )

{

$tFile = get-item (resolve-path $inFile)

$outFile = $tFile.Fullname -replace ($tFile.Extension + "`$"),".$type"

}

if ( (test-path $outFile) -and (! $force) ) { "File \'$outFile\' exists, exiting"; exit }

# make sure we have an encoder before changing anything on

# the filesystem

$codecs = [drawing.imaging.ImageCodecInfo]::GetImageEncoders() |

foreach { $h = @{} } { $h.($_.formatdescription) = $_ } { $h }

$encoder = $codecs.$type

if ( ! $encoder )

{

"No encoder of type \'$type\', exiting";

"Available encodings are: " + [string]::Join(", ", $h.keys)

exit

}

# This hoop is needed because resolve-path needs

# the file to actually exist. We shouldn\'t get here

# unless the file doesn\'t exist, or we\'re going to remove it

# by force.

if ( test-path $outFile ) { remove-item $outFile }

[void](new-item -type file $outFile)

$outFile = (resolve-path $outFile).path

remove-item $outFile

# read the image

$image = [system.drawing.image]::FromFile($iFile)

$image.Save($outFile, $encoder.FormatId)

$image.Dispose()

# Get the file we just created

get-item $outFile

但是有一点问题就是使用前必须[reflection.assembly]::LoadWithPartialName("System.drawing")，加在脚本里也行
使用方法 ./script.msh xxxx.bmp [gif] [new.gif] [-force]
如果省略后面三个参数默认就是用相同文件名以gif生成，此外还支持TIFF, JPEG, PNG, BMP。-force是当生成文件存在时强制覆盖

有人评论说，这种脚本太复杂了，一些命令行工具加上一个简单的批处理就够了。确实如此，但是要注意的是，这个的脚本的特点就是不需任何executable，它调用那些只有C#(或别的什么)才能使用的功能，无须编译。
monad team的Bruce Payette说：This illustrates an important principle in Monad - progressive capability. Simple things are simple (e.g. calling a utility program) and complex things are possible (like directly using a .NET library). 这显示了monad的一个重要原则，自我改进的能力。简单的事情固然简单(比如，monad也可以调用可执行文件)，复杂的事情也变得可能(直接使用.net类库)。