Aliasing grep in find's -exec option

Question

I have these aliases in my ~/.bashrc

alias grep='grep --color=auto -H'
alias fgrep='fgrep --color=auto -H'
alias egrep='egrep --color=auto -H'

but they have no effect when I run find ... -exec grep ..., and I always have to provide those options manually.

Is there a way to tell find to rely on aliases in the -exec option's arguments? I'm thinking of configuration files, rather than other aliases.

Would it be unsafe in some way?

Answer 1

You can't use aliases like that. Aliases work only if they're used first in a long command sequence, the shell basically replaces the alias text with the actual command. When you enter a command, the shell first searches for an alias, then a function and so on. Command substitution/alias substitution doesn't work if you're using an alias in the middle of a command sequence.

Furthermore, the -exec flag of find, will always spawn a seperate process executing the binary, neither an alias, nor a function, that's hard coded.

Answer 2

Some shells allow aliases to be expanded anywhere in the command line - for example, zsh has the concept of a global alias, alias -g 'grep=grep --color=auto -H'

If your interactive shell is bash however, aliases are only expanded when they appear as the first word of a command, so you would need to wrap the grep call in a shell, and invoke the shell in a way that causes your ~/.bashrc file to be read, as though in an interactive shell session.

For example

find . -name '*.txt' -exec bash -ic 'for f do grep foo "$f"; done' find-bash {} +

AFAIK it's not unsafe in any way - however it has some overhead and is hardly more convenient than simply supplying the desired options to grep directly.