Determine if a file contains a specific character

The code below reads through a file a character at a time counting the number of times the letter 'o' appears in the file.

Code

// '/path/to/file.txt' contains the following contents:
// I love the Lasso Rhino!

local(f) = file('/path/to/file.txt', io_file_o_rdonly, file_modeChar)
handle => { #f->close }

local(my_count)  = 0
local(next_char) = #f->get
while(#next_char) => {
    if(#next_char == 'o' or #next_char == 'O') => {
        #my_count += 1
    }
    #next_char = #f->get
}
#my_count

Result

3