Page 126 - DCAP303_MULTIMEDIA_SYSTEMS

Multimedia Systems

notes Text editors geared for professional computer users place no limit on the size of the file being
opened. In particular, they start quickly even when editing large files, and are capable of editing
files that are too large to fit the computer’s main memory. Simpler text editors often just read files
into an array in RAM. On larger files this is a slow process, and very large files often do not fit.
The ability to read and write very large files is needed by many professional computer users.
For example, system administrators may need to read long log files. Programmers may need
to change large source code files, or examine unusually large texts, such as an entire dictionary
placed in a single file.
If a file is copied into a word processing program from a text editor, caution
must be taken to save the file as a “.txt” file so that it will be read correctly.
Failure to do so may result in special characters being inserted where they
were not needed and can leave your document unreadable.
features of text editors:
:
• string searching algorithm Search string with a replacement string. Different methods are
employed, Global(ly) Search And Replace, Conditional Search and Replace, Unconditional
Search and Replace.

• Cut, copy, and paste: Most text editors provide methods to duplicate and move text within
the file, or between files.
• text formatting: Text editors often provide basic formatting features like line wrap, auto-
indentation, bullet list formatting, comment formatting, and so on.
• Undo and redo: As with word processors, text editors will provide a way to undo and
redo the last edit. Often—especially with older text editors—there is only one level of edit
history remembered and successively issuing the undo command will only “toggle” the last
change. Modern or more complex editors usually provide a multiple level history such that
issuing the undo command repeatedly will revert the document to successively older edits.
A separate redo command will cycle the edits “forward” toward the most recent changes.
The number of changes remembered depends upon the editor and is often configurable by
the user.

• Data transformation: Reading or merging the contents of another text file into the file
currently being edited. Some text editors provide a way to insert the output of a command
issued to the operating system’s shell.
• ability to handle Utf-8 encoded text.
• filtering: Some advanced text editors allow the editor to send all or sections of the file
being edited to another utility and read the result back into the file in place of the lines
being “filtered”. This, for example, is useful for sorting a series of lines alphabetically or
numerically, doing mathematical computations, and so on.
• syntax highlighting: Contextually highlights software code and other text that appears in
an organized or predictable format.
specialized editors

Some editors include special features and extra functions, for instance:
• Source code editors are text editors with additional functionality to facilitate the production
of source code. These often feature user-programmable syntax highlighting, and coding
tools or keyboard macros similar to an HTML editor.
• Folding editors includes so-called “orthodox editors” that are derivatives of Xedit. The
specialized version of folding is usually called outlining.

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