#!/usr/local/bin/e

pragma.syntax("0.9")

##
# The find function from the E Tutorial, modified to show the
# pathname.
# Prints all lines of a given file that contains a given substring.
#
def 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.
#
def findall(dirfile, ext, substring) {
    if (dirfile.isDirectory()) {
        for file in dirfile {
            findall(file, ext, substring)
        }
    } else if (dirfile.getName().endsWith(ext)) {
        find(dirfile, substring)
    }
}
 
def args := interp.getArgs()
if (args.size() != 3) {
    throw("usage: findall.e rootname extension substring")
}
def root := <file>[args[0]]
findall(root, args[1], args[2])