Bash: find -exec from a function

Question

I want to use a find -exec from a bash function. I know I need to terminate the -exec with a {} \;, but I can't find the proper way of doing it!

I tried :

find $SEARCHPATH -name \"${FILEPAT}.[ch]\" -exec grep --color -aHn \"$GREPPATTERN\" {} \;
find $SEARCHPATH -name \"${FILEPAT}.[ch]\" -exec grep --color -aHn \"$GREPPATTERN\" '{}' \;
find $SEARCHPATH -name \"${FILEPAT}.[ch]\" -exec grep --color -aHn \"$GREPPATTERN\" \{\} \;
find $SEARCHPATH -name \"${FILEPAT}.[ch]\" -exec grep --color -aHn \"$GREPPATTERN\" '{}' ';'

And many other, but I can't get anything to work. Most of the time I get find: missing argument to '-exec' And when find accepts the syntax I get no results for simple request like:

find . -name "*.[ch]" -exec grep --color -aHn "e" {} \;

Would someone help me with this one? Thanks!

Answer 1

Don't escape the quotes around the arguments -- when you do that, the quotes are treated as part of the arguments, and it's e.g. looking for files with actual quotes in the filename. Use something like this:

f() {
    searchpath=$1
    filepat=$2
    greppattern=$3
    find "$searchpath" -name "$filepat.[ch]" -exec grep --color -aHn "$greppattern" {} \;
}

[EDIT] To expand my comment about the quotes being treated as part of the arguments: quotes in a command line affect how the text inside them is parsed. Double-quotes allow variable references ('$varname`) to be expanded and a few other things, but not much else. Once they've had this effect, they are removed (i.e. they are not passed on to the command itself). To see this, let's define a function that just prints its arguments, and see what it actually receives from various command lines:

$ printargs() { printf "  <%s>\n" "$@"; }
$ printargs one two
  <one>
  <two>
$ printargs "one" "two"  # The quotes will be removed before printargs sees them
  <one>
  <two>
$ printargs "one two"   # The quotes make the two words into one argument, but again aren't passed on to printargs
  <one two>
$ printargs "one" 'two' three   # Single-quotes are also removed
  <one>
  <two>
  <three>

Similar things happen with variables:

$ var="one two"   # Note that the quotes are removed before the value is stored in $var
$ printargs $var    # Variable is substituted, then its value is parsed into separate words
  <one>
  <two>
$ printargs "$var"   # Double-quotes here allow the variable to be expanded, but prevent further parsing
  <one two>
$ printargs '$var'   # Single-quotes prevent even variable expansion
  <$var>

If you escape the quotes, however, they don't have any of these effects; they're just treated as parts of the argument:

$ printargs \"one\" \'two\' \"three four\"
  <"one">
  <'two'>
  <"three>
  <four">
$ printargs \"$var\"
  <"one>
  <two">

...this is almost never what you want. In particular, with the find command:

$ searchpath=.
$ filepat='*'
$ greppattern='#ifdef'
$ printargs "$searchpath" -name "$filepat.[ch]" -exec grep --color -aHn "$greppattern" {} \;
  <.>
  <-name>
  <*.[ch]>
  <-exec>
  <grep>
  <--color>
  <-aHn>
  <#ifdef>
  <{}>
  <;>
$ printargs "$searchpath" -name \"$filepat.[ch]\" -exec grep --color -aHn \"$greppattern\" {} \;
  <.>
  <-name>
  <"*.[ch]">
  <-exec>
  <grep>
  <--color>
  <-aHn>
  <"#ifdef">
  <{}>
  <;>

...in the second one (with escaped quotes) the quotes are passed to find and it treats them as part of the filename pattern, looking for files with double-quotes in the name. If it manages to find any, the same thing would happen with the grep command -- it'd be looking for #ifdef's with double-quotes around them.