Applescript does not seem to properly escape strings. What am I doing wrong?
Example:
set abc to "funky-!@#'#\"chars"
display dialog abc
display dialog quoted form of abc
Expected / Desired Output:
funky-!@#'#"chars
'funky-!@#\'#"chars'
Actual Output:
funky-!@#'#"chars
'funky-!@#'\''#"chars'
As you can see, it appears that in the actual output Applescript is adding and escaping an extra '
I would be OK with the end characters being either ' or " and I would also be fine with both the single and double quotes being escaped - but it appears that only the single quotes are actually escaped.
Backslashes aren't usually interpreted inside single quotes in shells.
Enclosing characters in single quotation marks preserves the literal value of each character within the single quotation marks. A single quotation mark cannot occur within single quotation marks.
A backslash cannot be used to escape a single quotation mark in a string that is set in single quotation marks. An embedded quotation mark can be created by writing, for example: 'a'\''b', which yields a'b.
However they are interpreted by echo in sh, which is the shell used by do shell script:
do shell script "echo " & quoted form of "\\t" --> "\t"
Unsetting xpg_echo makes it behave like the echo in bash:
do shell script "shopt -u xpg_echo; echo " & quoted form of "\\t" --> "\\t"
Often it's simpler to use HEREDOC redirection instead:
do shell script "rev <<< " & quoted form of "a\\tb" --> "b\\ta"