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Unformatted text preview: inprog.cz, where .c and .z are used to indicate that it is a C
language program file that has been compressed using the Ziv-Lempel
compression algorithm. In such file names, the second and subsequent parts are
called file extensions. File extensions usually indicate something about the file and
are often used by applications to check for the intended type of file before
operating on it. For example, a C language compiler may actually insist that the
files it is to compile end in 4c, and it may refuse to compile them if they do not.
Some applications automatically supply their own extensions, such as .doc (for a Microsoft Word file) or .wk4 (for a Lotus 1-2-3 file). Some typical file extensions
and their meanings are shown in Figure 14.17.
.gif Its meaning
Basic source program file
C source program file
Fortran source program file
Pascal source program file
Object file (compiler output, not yet
Executable binary program file
Library of .obj files used by the
Text file for HELP command
Online manual page file
General text file
Microsoft word document file
Microsoft windows sound file
Lotus 1-2-3 spreadsheet file
Microsoft Excel spreadsheet file
JPEG graphics file
GIF graphics file Figure 14.17. Some typical file extensions and their meaning.
Directories are used by operating systems to map file names to their corresponding
file attributes and file data, and also to provide greater flexibility to users in file
naming. How directories help in achieving these objectives is briefly explained
A directory has a number of entries, one per file. As shown in Figure 14.18, each
entry contains a file name, the attributes of the file or pointer to the data structure
containing the attributes, and pointer to the file data (disk address where the file
data is stored).
File File attributes or pointer to data Pointer to file...
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This document was uploaded on 04/07/2014.
- Spring '14