#!/usr/local/bin/e
 
##
# The find function from the E Tutorial, modified to show the
# pathname.
# Prints all lines of a given file that contains a given substring.
#
define find(file, substring) {
    for num => line in file {
        if (line indexOf(substring) != -1) {
            print(file getPath + ":" + num + ":" + line)
        }
    }
}
 
##
# The findall function from the E Tutorial, modified to take an
# extension parameter.
# Recursively walks a directory tree, and prints all lines in .txt
# files that contain the given substring.
#
define findall(dirfile, ext, substring) {
    if (dirfile isDirectory) {
        for file in dirfile {
            findall(file, ext, substring)
        }
    } else if (dirfile getName endsWith(ext)) {
        find(dirfile, substring)
    }
}
 
define args := interp getArgs
if (args size != 3) {
    throw("usage: findall.e rootname extension substring")
}
define root := file: (args[0])
findall(root, args[1], args[2])