CODEWITHSUNDEEP
applescript
Charles Johnson
Charles Johnson

Reputation: 751

Calling a shell command from Applescript with quotes

This seems like it should be simple, but I'm pulling out my remaining hair trying to get it to work. In a shell script I want to run some Applescript code that defines a string, then pass that string (containing a single quote) to a shell command that calls PHP's addslashes function, to return a string with that single quote escaped properly.

Here's the code I have so far - it's returning a syntax error.

STRING=$(osascript -- - <<'EOF'
set s to "It's me"
return "['test'=>'" & (do shell script "php -r 'echo addslashes(\"" & s & "\");") & "']"
EOF)
echo -e $STRING

It's supposed to return this:

['test'=>'It\'s me']

Upvotes: 1

Views: 840

Answers (2)

mklement0
mklement0

Reputation: 440172

To complement Gordon Davisson's helpful answer with a pragmatic solution:

Shell strings cannot contain \0 (NUL) characters, but the following sed command emulates all other escaping that PHP's (oddly named) addslashes PHP function performs (\-escaping ', " and \ instances):

string=$(osascript <<'EOF'
  set s to "It's me\\you and we got 3\" of rain."
  return "['test'=>'" & (do shell script "sed 's/[\"\\\\'\\'']/\\\\&/g' <<<" & quoted form of s) & "']"
EOF
)
printf '%s\n' "$string"

yields

['test'=>'It\'s me\\you and we got 3\" of rain.']

Note the use of quoted form of, which is crucial for passing a string from AppleScript to a do shell script shell command with proper quoting.

Also note how the closing here-doc delimiter, EOF, is on its own line to ensure that it is properly recognized (in Bash 3.2.57, as used on macOS 10.12, (also when called as /bin/sh, which is what do shell script does), this isn't strictly necessary, but Bash 4.x would rightfully complain about EOF) with warning: here-document at line <n> delimited by end-of-file (wanted 'EOF')

Upvotes: 1

Gordon Davisson
Gordon Davisson

Reputation: 126038

First, when asking a question like this, please include what's happening, not just what you're trying to do. When I try this, I get:

42:99: execution error: sh: -c: line 0: unexpected EOF while looking for matchin
sh: -c: line 1: syntax error: unexpected end of file (2)

(which is actually two error messages, with one partly overwriting the other.) Is that what you're getting?

If it is, the problem is that the inner shell command you're creating has quoting issues. Take a look at the AppleScript snippet that tries to run a shell command:

do shell script "php -r 'echo addslashes(\"" & s & "\");"

Since s is set to It's me, this runs the shell command:

php -r 'echo addslashes("It's me");

Which has the problem that the apostrophe in It's me is acting as a close-quote for the string that starts 'echo .... After that, the double-quote in me"); is seen as opening a new quoted string, which doesn't get closed before the end of the "file", causing the unexpected EOF problem.

The underlying problem is that you're trying to pass a string from AppleScript to shell to php... but each of those has its own rules for parsing strings (with different ideas about how quoting and escaping work). Worse, it looks like you're doing this so you can get an escaped string (following which set of escaping rules?) to pass to something else... This way lies madness.

I'm not sure what the real goal is here, but there has to be a better way; something that doesn't involve a game of telephone with players that all speak different languages. If not, you're pretty much doomed.

BTW, there are a few other dubious shell-scripting practices in the script:

  • Don't use all-caps variable named in shell scripts. There are a bunch of all-caps variables that have special meanings, and if you accidentally use one of those for something else, weird results can happen.
  • Put double-quotes around all variable references in scripts, to avoid them getting split into multiple "words" and/or expanded as shell wildcards. For example, if the variable string was set to "['test'=>'It\'s-me']", and you happened to have files named "t" and "m" in the current directory, echo -e $string will print "m t" because those are the files that match the [] pattern.
  • Don't use echo with options and/or to print strings that might contain escapes, since different versions treat these things differently. Some versions, for example, will print the "-e" as part of the output string. Use printf instead. The first argument to printf is a format string that tells it how to format all of the rest of the arguments. To emulate echo -e "$string" in a more reliable form, use printf '%b\n' "$string".

Upvotes: 2

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