indigo 52 % isearch 
Enter input file name: UFO.txt
File 'UFO.txt' does not exist.
indigo 53 % isearch
Enter input file name: ghost.txt
File 'ghost.txt' is not readable.
indigo 55 % isearch
Enter input file name: phone_book
Enter the word to search for: alex
Case-sensitive (y/n)? n
alex johnson 	(416) 555-1234 	family doctor	
Alexander Smith (905) 555-9876 	home renovation contractor
indigo 56 % isearch
Enter input file name: phone_book
Enter the word to search for: alex
Case-sensitive (y/n)? Y 
alex johnson 	(416) 555-1234 	family doctor	
indigo 69 % isearch
Enter input file name: phone_book
Enter the word to search for: Alex
Case-sensitive (y/n)? Z
Invalid option
Case-sensitive (y/n)? a
Invalid option
Case-sensitive (y/n)? Y
Alexander Smith (905) 555-9876 	home renovation contractor
indigo 71 % isearch
Enter input file name: phone_book
Enter the word to search for: microwave
Case-sensitive (y/n)? y
Word 'microwave' not found.
indigo 72 %

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indigo 55 % icount
Enter input file name: UFO.txt
File 'UFO.txt' does not exist.
indigo 56 % icount
Enter input file name: ghost.txt
File 'ghost.txt' is not readable.
indigo 59 % icount
Enter input file name: phone_book
Count lines, words, characters or all three (l, m, c, a)? Z
Invalid option
Count lines, words, characters or all three (l, m, c, a)? t
Invalid option
Count lines, words, characters or all three (l, m, c, a)? L
File 'phone_book' contains 23 lines.
indigo 60 % icount
Enter input file name: phone_book
Count lines, words, characters or all three (l, m, c, a)? M
File 'phone_book' contains 125 words.
indigo 61 % icount
Enter input file name: phone_book
Count lines, words, characters or all three (l, m, c, a)? c
File 'phone_book' contains 985 characters.
indigo 62 % icount
Enter input file name: phone_book
Count lines, words, characters or all three (l, m, c, a)? a
File 'phone_book' contains 23 lines, 125 words, 985 characters.
indigo 63 % 

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indigo 75 % doublesp
Enter input file name: phone_book
Enter output file name: ghost.txt
File 'ghost.txt' not writable.
indigo 76 % doublesp
Enter input file name: phone_book
Enter output file name: new.txt
indigo 77 % doublesp
Enter input file name: phone_book
Enter output file name: new.txt
File 'new.txt' exists.
Append to it (y/n)? K
Invalid option
Append to it (y/n)? b
Invalid option
Append to it (y/n)? n
indigo 78 % doublesp
Enter input file name: phone_book
Enter output file name: new.txt
File 'new.txt' exists.
Append to it (y/n)? Y
indigo 79 % cat new.txt
This line was in the file before "doublesp" was executed.
This line also existed before "doublesp" was executed.
Ray Szeto       (416) 564-6786	friend

alex johnson 	(416) 555-1234 	family doctor
	
Tom Podstawka   (647) 579-3854	dentist

Greg Ivan       (905) 789-6703	neighbour

Nikola Sandic   (647) 209-7932	friend from work

Tim Yu          (416) 570-9522	Jill's coach

indigo 80 % cat phone_book
Ray Szeto       (416) 564-6786	friend
alex johnson 	(416) 555-1234 	family doctor	
Tom Podstawka   (647) 579-3854	dentist
Greg Ivan       (905) 789-6703	neighbour
Nikola Sandic   (647) 209-7932	friend from work
Tim Yu          (416) 570-9522	Jill's coach