This is only the interface and control for encryption programs. It calls the programs encfile, decfile and atma. Mainmenu This menu has full control of the whole program and provides very good interface to the user. It provides all the options and displays error messages when appropriate. It calls the menus from 1 to 5 when user selects the corresponding option. If user enters the wrong selection it displays the error message. When user selects to quit, it display the greeting message as well. (See attached programs printouts)
The problems encountered when coding the program This scripting language is really very easy to compare other programming languages. It has no syntax like semicolon etc. And also UNIX commands are very powerful. If use them in appropriate places program coding is very easy. The basic condition branching and control structures also very easy if knows how to use them. However the different kinds of quotes are confusing sometimes and they are very powerful tools. But when write the program and get some experience, it is not a problem. The hard part is 6-digit encryption program. It is very long and difficult to understand the codes. However it is structured by writing separate method for it and make little easy to understand.
Translation of a sentence from one language to another To do this, when user enters a sentence, program has to read all the words in the sentence. For example we use the command “read” to read three variables from key board at once. Therefore we can use this command to read many words from key-board; the problem is we have to decide how many words can be read at once. This is because all the sentences will not have the same number of words.
However we can write a program to read 20 words or 40 it does not a matter but some time these will be wasted, and if user enter very long sentence difficult to handle. Then from that sentence a word have to be selected and has to search for a same meaning in the dictionary in other language. Then we can display them together. Here we actually done only translation for each word in the sentence but not for the sentence? This is to say the grammar is different for each language. However it also can be done because for example nowadays when we type some words on Microsoft word it says grammar is not in order like this. That kind of program can be used to correct the sentences indeed.
This scripting langue provides ability to build own scripts for specified jobs. For example we can write very complex programs on it and can be accessed by one word. Then this program can be executed using one word as using other commands. When develop a program it must follow some kind of structures methods and has to use good tools. This is because it is easy to build and easy to understand developer and others. Therefore it reduces errors on the programs. Further more about this program, it helps to gain more about UNIX and UNIX commands. And also increases the programming talent.
GRAHAM GLASS, KING ABLES, UNIX for programmers and Users, second edition http://www.tldp.org