Glossary - E        A B C D E  F G H I J K L M N O P Q R S T U V W X

Echo - See Command Echoing.

End of Line (EOL) - An indication of the end of line in text files. Many conventions exist to represent EOL in ASCII files. The most common ones use one or two control characters: (1) CR, (2) CR followed by LF, (3) LF followed by CR, (4) LF. Windows text files normally use (2). UNIX/Linux and their variants use (4), and refer to the LF character as the new line (NL) character.

Environment - A set of variables and their values. Some variables are set before the start of Take Command. Others may be set at the command line using the SET command, or by your batch files. If a variable is defined, it has a value, which is a character string, and is at least 1 character long. A variable can be removed from the environment using the UNSET command, or by setting its value to an empty string. See also Master Environment and Passed Environment.

Environment Variable - The name of a single entry in the environment.

Error Level - A numeric value returned from an external command or, in some cases, from an internal command to indicate its result (e.g., success, failure, response to a question). Not all commands return an error level. Also known as Exit Code.

Escape Character -

1) The command processor escape character, used to suppress the normal meaning of, or to give special meaning to the immediately following character. The default  escape character in TCC is the caret (^). This may be modified using the Escape character configuration option or by using the /E option of the SETDOS command.

2) A control character, symbol ESC (ASCII: 27).

Escape Sequence - A sequence of text characters which has a special meaning and is not treated as normal text. For example, the character sequence <ESC>]K (where <ESC> represents the ASCII "escape" character, decimal value 27) will cause an ANSI X3.64 driver to clear the screen from the cursor to the end of the current line, rather than simply displaying the string ESC]K on the screen. Similarly, in Take Command, the escape sequence ^f on the command line is translated to a form feed, and is not treated as the literal characters ^f.

Executable Extension - A TCC feature which allows you to specify the application to be executed when a file with a particular extension is named at the command prompt.

Executable File - A file, usually with the extension .COM or .EXE, which can be loaded into memory and run as a program.

Exclusive OR or XOR - A logical combination of two true or false conditions. If both conditions are false or both conditions are true the result is false; if either condition is true and the other is false the result is true. See below.

Exit Code - The result code returned by an external command or an internal command. Internal commands return an exit code of 0 if successful, or non-zero if unsuccessful. External commands may, but need not return an exit code. See also Errorlevel.

Expansion :

       1) Command Line Expansion

       2) The inverse of compression.

Extended ASCII Character:  A legally invalid phrase, used for a character whose code is in the range 128 to 255, used as part of an extended set of 256 characters. The extension character set may include international language symbols, and box and line drawing characters. What is displayed or what is printed when such a character is used depends on the country setting, code page, and font.

Extended Directory Search - A TCC feature which maintains a directory search database or list, typically including all directories in your system, and allows you to change quickly to any directory in the list based on partial match of the directory you specify in the command.

Extended Key Code - The code for a key on the keyboard which has no representation in the standard ASCII character set, such as a function key, cursor key, or Alt plus another key.

Extended Parent Directory Names - A TCC feature which allows you to use additional periods in a directory name to represent directories which are successively higher in the directory tree.

Extended Wildcard - A TCC feature which extends the wildcard syntax and allows you to use multiple wildcard characters, and character ranges (e.g. [a-f] for the letters A through F). See also Wildcard.

Extension - The portion of a file name following the last period. For example, in the file name C:\DIR1\LETTER.JOHN.DAT the extension is .DAT.

External Command - A program directly executable by the operating system, as distinguished from an internal command, which is executed by TCC.

EXTPROC - A TCC feature which allows you to designate a specific external program to run a particular batch file.