Expand a POSIX path with prefix "~" (using AppleScript) - applescript

Question

StandardAdditions has the path to command and we can use it to get known locations.
For example, path to home folder returns a file reference to the user folder and if we want the posix path, we can do POSIX path of ((path to home folder) as text).
In Terminal.app we can use the tilde character (~) to represent the home folder.
How can we do this tilde expanding in AppleScript?

Answer 1

Started with OS X 10.10 you can easily access Cocoa classes and their functions and properties:
use framework "Foundation"
expandTilde("~/Desktop")
on expandTilde(givenPath)
-- create a temporary Obj-C/Cocoa NSString object with the givenPath
set tempCocoaString to current application's NSString's stringWithString:givenPath
-- call the object's stringByExpandingTildeInPath method
-- to create a new path with expanded tilde
return (tempCocoaString's stringByExpandingTildeInPath) as string
end expandTilde
In 10.9 you have to define such handlers in Scripting Libraries, that's less nice than it sounds. But in 10.10 this works out of the box!

Answer 2

Zero
There is more than one way to skin that cat. As you pointed out, or with the simple:
system attribute "HOME"
And then concatenate on the remaining path.

Answer 3

More coming soon
How to expand a posix path that can start with the tilde character ~?
(~ represents the home folder)
Here the script+demo:
#
demo()
# ------------------------------------------------------------
#
# expandTildeInPath ( localPath, outputStyle )
#
# ------------------------------------------------------------
# When outputStyle is true : returns posix path
# When outputStyle is false : returns alias
# ------------------------------------------------------------
# localPath format:
# ------------------------------------------------------------
# • posix path - a posix path (can start with a tilde "~")
# • alias
# • path (text) with ":" => (alias as text) produces this
# ------------------------------------------------------------
on expandTildeInPath(localPath, outputStyle)
# ------------------------------------------------------------
# If necessary, convert localPath to text and posix path:
# ------------------------------------------------------------
if (class of localPath is alias) then
# alias
set localPath to POSIX path of (localPath as text)
else if (class of localPath is text) and (localPath contains ":") then
# (fileAlias as text) produces such a colon delimited path:
set localPath to POSIX path of localPath
end if
set resultPath to localPath
# -------------------------------
# If necessary, expand tilde:
# -------------------------------
if localPath starts with "~" then
# input is like: "~", "~/" or something with a sub path, like "~/Movies"
set homeFolder to POSIX path of ((path to home folder) as text)
if (localPath = "~") or (localPath = "~/") then
# no sub-path
set resultPath to homeFolder
else
if not (localPath starts with "~/") then
# this is not a valid path to expand but an item that starts with "~"
return localPath
end if
# add sub-path
set subPath to ((characters 3 thru -1) of aPath) as text
set sDel to "/"
if (subPath starts with sDel) then set sDel to ""
set resultPath to homeFolder & sDel & subPath
end if
end if
# -------------------------------
# return posix path or alias:
# -------------------------------
if outputStyle then
return (POSIX path of resultPath)
else
# the location must exist or "as alias" throws an error.
try
set a to (resultPath as POSIX file) as alias
return a
on error
log "*** Error ***" & resultPath & " does not exist"
return localPath
end try
end if
end expandTildeInPath
# ------------------------------------------------------------
# Sub Routines for Demo
# ------------------------------------------------------------
on demo()
set asAlias to false
set asPosixPath to true
# Does not expand since its a name that starts with "~":
logDemo("~testFile", asAlias)
# FolderThatDoesNotExist:
logDemo("~/FolderThatDoesNotExist", asAlias) # this throws an error (in the log) and returns the unchanged input
logDemo("~/FolderThatDoesNotExist", asPosixPath) # returns expanded posix path (existing or not)
# Main Usage
logDemo("~", asPosixPath)
logDemo("~", asAlias)
logDemo("~/", asPosixPath)
logDemo("~/", asAlias)
logDemo("~/Documents/", asPosixPath)
logDemo("~/Documents/", asAlias)
# convert a posix path like "/Applications" to alias
logDemo("/Applications", asAlias)
set input to "~/Music/iTunes/iTunes Library.xml"
set filePosixPath to expandTildeInPath(input, asPosixPath)
set fileAlias to expandTildeInPath(input, asAlias)
log quoted form of input
log quoted form of filePosixPath
log fileAlias
logLine()
# Using alias with Finder is so easy:
tell application "Finder"
if exists fileAlias then
# activate
# reveal fileAlias
end if
end tell
# --------------------------
# Other input formats:
# --------------------------
# This is also possible (not intended but it works):
# we can use text paths (containing ":"):
logDemo((path to documents folder as text), false)
# we can use aliases:
# (makes no sense at all when we return an alias but this is to show that it works)
logDemo((path to documents folder), false)
# Same as above but output as posix path:
logDemo((path to documents folder as text), true)
logDemo((path to documents folder), true)
end demo
on logLine()
log "---------------------------------------------"
end logLine
on logDemo(inputPath, outputStyle)
set a to expandTildeInPath(inputPath, outputStyle)
if outputStyle then
log "input: " & inputPath & " output: " & quoted form of a
else
log "input: " & inputPath & " output (next line): "
log a # don't mix with text or it does not show the "alias" in the log
end if
logLine()
end logDemo
# ------------------------------------------------------------
Here a little addition to show the system attributes:
set saList to system attribute
repeat with sa in saList
log quoted form of sa & " = " & quoted form of (system attribute sa)
end repeat

Answer 4

Here's a handy applescript one-liner that resolves any posix path beginning with a tilde (Sample path included.) Afterwards you'll find sample conversions to other path formats.
set psxPTH to "~/Library/Scripts/"
if character 1 of psxPTH contains "~" then set psxPTH to POSIX path of (path to home folder) & text (2 + (offset of "~" in psxPTH)) thru -1 of psxPTH
------>"/Users/Mr.Science/Library/Scripts/"
--other steps after the posix is resolved...
set hfsPTH to (POSIX file psxPTH) as text
------> "Macintosh_Harddrive:Users:Mr.Science:Library:Scripts:"
set alsPTH to alias hfsPTH
------> alias "Macintosh_Harddrive:Users:Mr.Science:Library:Scripts:"
tell application "Finder" to set vrbspth to item alsPTH
------> folder "Scripts" of folder "Library" of folder "Mr.Science" of folder "Users" of startup disk of application "Finder"