The problem is that
grep to recursively search through all files in the directory. So, you can't combine it with a specific group of files. Therefore, you can either use
find as suggested by @KM., or shell globbing:
$ shopt -s globstar
$ grep -- "->-" **/*.tex
shopt command activates bash's globstar feature:
If set, the pattern ** used in a pathname expansion con‐
text will match all files and zero or more directories
and subdirectories. If the pattern is followed by a /,
only directories and subdirectories match.
You then give
**/*.tex as a pattern and that will match all
.tex files in the current directory and any subdirectories.
If you're using
zsh, there's no need for the
shopt (which is a bash feature anyway) since
zsh can do this by default.