UNIX Shell Scripts All problems have the same weight. Problem 1 Write a script named isearch to allow users to input a file name and a word/pattern. Search the file for the word/pattern and display the lines that contain the word/pattern on the standard output. If the word/pattern is not found, display a message. indigo 20% isearch Enter input file name: phone_book.txt Enter the word to search for: from Case-sensitive (y/n)? n Nikola Sandic ROB Oxley (647) 209-7932 friend from work (416) 723-8759 friend from university If the word/pattern is not found, display a message. Word 'from' not found. Problem 2 Write a script named icount to allow users to input a file name and display on the standard output the number of lines, words or characters in the file. indigo 21% icount Enter input file name: phone_book.txt Count lines, words, characters or all three (1, m, c, a)? b. Invalid option Count lines, words, characters or all three (1, m, c, a)? m File 'phone_book.txt' contains 125 words. Problem 3 Write a script named all files to allow a user to list all (ordinary) files in the current directory, one per line, but not the sub-directories in the current directory. (Note: command '1s' displays all files and directories.) indigo 22% allfiles allfiles lab3a.c lab3b.c lab3b_out.txt Problem 4 Write a script named fdisplay to allow a user to input a file name and an option to display the content of the file (entire file, entire file one page at a time, first 10 lines, last 10 lines). Display the content of the file as the user specifies. If the user enters an invalid option, display an error message and ask for a correct option. indigo 23 fdisplay Enter input file name: phone_book.txt Enter option (e, p, f, 1): a Invalid option Enter option (e, p, f, 1): p File is displayed one page at a time Problem 5 Write a script named doublesp to allow a user to input an input and an output file name. Copy the content from the input file to the output file, adding a blank line between every two lines of the input file (double spacing). If the output file exists, display the message shown below. If the user answers yes then append the output to the file. If the user answers no, exit and do nothing (i.e., do not overwrite an existing file). indigo 24 doublesp Enter input file name: phone_book.txt Enter output file name: outfile.txt File outfile.txt' exists. Append to it (y/n)? y Problem 6 Write a script named addlines to allow a user to enter an input and an output file name. Copy the content from the input file to the output file, line by line, adding a line number at the beginning of each copied line. Add a space after the colon before copying the line. If the output file exists, display a message as above. If the user answers yes then append the output to the file. If the user answers no, exit and do nothing. indigo 25 addlines Enter input file name: phone_book.txt Enter output file name: outfile.txt indigo 26 cat outfile.txt 1: Ray Szeto 2: alex johnson 3: Tom Podstawka (416) 564-6786 friend (416) 555-1234 family doctor (647) 579-3854 dentist Notes ⚫ An input file must exist and be readable before being read from. ⚫ An existing output file must be writable before being written to. . Assume that all inputs from the user are case-insensitive, except file names. (Unix file names are case-sensitive, so we keep the same convention.) For example, the user may enter either 'y' or 'Y'. Assume that all input files are text files containing no back slash characters. See file unix_output.txt for more examples. Do not use any text processing utility such as "sed" or "awk". • Make sure to use the same error messages or confirmation messages as specified, because the automatic grading script will use "grep" to look for these messages. • Make sure to name the submitted files (scripts) exactly as specified, because the automatic grading script will to look for those exact file names. ⚫ Submit only the Unix scripts. Do not submit output files. Sample Error Messages Enter input file name: yourfile.txt File 'yourfile.txt' does not exist. Enter input file name: ourfile.txt File 'ourfile.txt' is not readable. Enter output file name: hisfile.txt File 'hisfile.txt' is not writable. Enter output file name: outfile.txt File 'outfile.txt' exists. Append to it (y/n)? n In the above examples, simply exit the script upon a file error, or an answer 'n' or 'N'. 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% 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 (1, m, c, a)? Z Invalid option Count lines, words, characters or all three (1, m, c, a)? t Invalid option Count lines, words, characters or all three (1, 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 (1, 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 (1, 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 (1, m, c, a)? a File 'phone_book' contains 23 lines, 125 words, 985 characters. indigo 63% 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 alex johnson Tom Podstawka (416) 564-6786 friend (416) 555-1234 family doctor (647) 579-3854 dentist (905) 789-6703 neighbour Greg Ivan. Nikola Sandic (647) 209-7932 friend from work Tim Yu (416) 570-9522 Jill's coach indigo 80% cat phone_book Ray Szeto alex johnson (416) 564-6786 friend family doctor (416) 555-1234 (647) 579-3854 dentist neighbour Tom Podstawka Greg Ivan Nikola Sandic (905) 789-6703 (647) 209-7932 Tim Yu (416) 570-9522 friend from work Jill's coach