I have the following code in bash and I wonder on whether I can get rid of \+ and simply use +
find "$fdir" \
-type f -name "*.org" -o -name "*.texi" \
-exec head -n "$n" {} \+ \
| grep --color -e ^ -e '^==>.*'
+ is not a special character in any shell and doesn't need quoted.
^ is special in a few shells though including the Thompson shell (first UNIX shell), Bourne shell, fish, rc, es, zsh with extendedglob. {} needs to be quoted in rc, and older versions of fish. *, (, ), > are special in most shells.
Note that not all head implementations accept more than one argument. The GNU implementation of head does and will print those ==> header lines but only when passed more than one argument or with the -v option.
Also note that AND (implied) has precedence over OR (-o) in find (see `find` with multiple `-name` and `-exec` executes only the last matches of `-name`), so:
find "$fdir" \
-type f '(' -name '*.org' -o -name '*.texi' ')' \
-exec head -v -n "$n" '{}' + \
| grep --color -e '^' -e '^==>.*'
(using '...' quoting in place of "..." or \ quoting for consistency only).
would work in Bourne-like, csh-like shells and fish. In rc/es, you'd need to remove the double quotes. In csh/tcsh, you'd replace "$fdir" with $fdir:q so it works even if $fdir contained newline characters.
The quotes around $fdir and $n are only needed in Bourne-like shells other than zsh and csh-like shells. " is not a quoting operator in rc/es. \ is not a quoting operator in rc either (though does do line continuation like in other shells).
See How to use a special character as a normal one in Unix shells? for what characters are special in which shell and how to escape / quote them.
'('and')'. – Pietru Jul 21 '21 at 18:55-type f -name '*.org' -o -name '*.texi' -exec...is actually interpreted as'(' -type f -name '*.org' ')' -o '(' -name '*.texi' -exec... ')'. See `find` with multiple `-name` and `-exec` executes only the last matches of `-name` – Stéphane Chazelas Jul 21 '21 at 18:59