If you are new to Linux, you may see certain file types that you do
not recognize because of their unfamiliar
extension. A file's extension is the last part of
a file's name after the final dot (in the file
sneakers.txt, "txt" is that
14.2.1. Compressed and Archived Files
.bz2 — a file compressed with
.gz — a file compressed with
.tar — a file archived with
tar (short for tape
archive), also known as a tar
.tbz — a tarred and bzipped
.tgz — a tarred and gzipped
.zip — a file compressed with ZIP
compression, commonly found in MS-DOS applications. Most compressed
files for Linux use the gzip compression, so
finding a .zip archive for Linux files is rare.
For information on working with bzip2,
gzip, and tar files, refer to Section 14.3 File Compression and Archiving.
14.2.4. Programming and Scripting Files
.c — a C program language source code
.cpp — a C++ program language source
.h — a C or C++ program language
.o — a program object file
.pl — a Perl script
.py — a Python script
.so — a library file
.sh — a shell script
.tcl — a TCL script
But file extensions are not always used, or used consistently. So what
happens when a file does not have an extension, or the file does not
seem to be what the extension says it is supposed to be?
That is when the file command can be helpful.
For example, you find a file called saturday
without an extension. Using the file command, you can
tell what type of file it is by typing:
In the example, the command file saturday will
display ASCII text, telling you it is
a text file. Any file that is designated as a text file should be
readable by using the cat, more,
or less commands, or by using a text editor such as
gedit or vi.
To learn more about file, read the
man page by typing man file.
For more information on helpful commands for reading files, see
Chapter 13 Shell Prompt Basics.