Description:

Strings are an important part of programming. They are used to transfer all sorts of data between the user and program, as well as from program to program. Humans communicate with streams because they are flexible enough to encode words and variable length sentences. A common use of computers is in word processing and in editing files. In this machine problem we will be creating a simple text editor. It will have the following capabilities:

1. Be able to search for a string anywhere in the file

2. Report the location of the string found, so it can be used for further processing

3. Be able to change part of the file (a string in the file)

4. Allow for ALL matching strings in a file to be updated at the same time, if the user desires

5. Allow for deletion of parts of a string

6. Allow for insertion of characters into the file

In this program you will:

1. Read in a file name from the input file

2. You will create a single string from the file without doing any preprocessing or changing the file in any way

3. You will then request directions for editing the file. Possible commands are:

a. E - exit the file and write it to a specified output file

b. S - search the file for some string, reporting the character number where the string starts and printing the text surrounding the string for +/- 25 characters. That is, if the search string is 10 characters long, then the text shown should be 60 characters long. This will consist of the preceding 25 characters, the 10 characters in the search string, and the following 25 characters. Place a space between the search string and the other characters shown

c. R - replace a string at position X with the string given

d. D - delete a search string

e. A - replace all strings matching the search string with the string given

f. X - delete all instances of a search string in the file

g. W - writes the entire file out to the screen (as presently edited)

4. The inputs given to you (in order) will be

a. The input file to edit

b. The output file for writing the edited file out

c. Command, followed by

i. Search string (if required)

ii. Replacement string (if required)

5. Files required will be provided with the machine problem. They will be named

a. MP3ins.dat - the instructions to be run on using your code

b. MP3data.dat - the data file containing the file to be edited