| Chapter 1. Computer Dictionary | ||
|---|---|---|
|
 |
|
| Chapter 1. Computer Dictionary | ||
|---|---|---|
|
|
|
|
Expands to the full pathname used to invoke this instance of bash. [40]
Expands to the version number of this instance of bash. [40]
The search path for the cd command. This is a colon-separated list of directories in which the shell looks for destination directories specified by the cd command. A sample value is '.:~:/usr''. [40]
If this parameter is set when bash is executing a shell script, its value is interpreted as a filename containing commands to initialize the shell, as in .bashrc. The value of ENV is subjected to parameter expansion, command substitution, and arithmetic expansion before being interpreted as a pathname. PATH is not used to search for the resultant pathname. [40]
A colon-separated list of suffixes to ignore when performing filename completion (see READLINE below). A filename whose suffix matches one of the entries in FIGNORE is excluded from the list of matched filenames. A sample value is '.o:~''. [40]
The history number, or index in the history list, of the current command. If HISTCMD is unset, it loses its special properties, even if it is subsequently reset. [40]
If set to a value of ignorespace, lines which begin with a space character are not entered on the history list. If set to a value of ignoredups, lines matching the last history line are not entered. A value of ignoreboth combines the two options. If unset, or if set to any other value than those above, all lines read by the parser are saved on the history list. [40]
The name of the file in which command history is saved. (See HISTORY below.) The default value is ~/.bash_history. If unset, the command history is not saved when an interactive shell exits. [40]
The maximum number of lines contained in the history file. When this variable is assigned a value, the history file is truncated, if necessary, to contain no more than that number of lines. The default value is 500. [40]
The number of commands to remember in the command history (see HISTORY below). The default value is 500. [40]
The home directory of the current user; the default argument for the cd builtin command. [40]
Contains the name of a file in the same format as /etc/hosts that should be read when the shell needs to complete a hostname. The file may be changed interactively; the next time hostname completion is attempted bash adds the contents of the new file to the already existing database. [40]
Automatically set to a string that uniquely describes the type of machine on which bash is executing. The default is system-dependent. [40]
In UNIX, the $IFS variable separates commands. It is usually conigured to be the semicolon (;) and newline characters. However, it can be reconfigured to be other characters as well. Data-driven attacks will sometimes seek to reset the IFS variable (e.g. IFS=x), then cause execution within the data field wihtout having to insert shell metacharacters. Tidbit: On Linux, the $FF variable may also be used like $IFS. [96]
The Internal Field Separator that is used for word splitting after expansion and to split lines into words with the read builtin command. The default value is '<space><tab><newline>''. [40]
Controls the action of the shell on receipt of an EOF character as the sole input. If set, the value is the number of consecutive EOF characters typed as the first characters on an input line before bash exits. If the variable exists but does not have a numeric value, or has no value, the default value is 10. If it does not exist, EOF signifies the end of input to the shell. This is only in effect for interactive shells. [40]
The filename for the readline startup file, overriding the default of ~/.inputrc (see READLINE below). [40]
Each time this parameter is referenced, the shell substitutes a decimal number representing the current sequential line number (starting with 1) within a script or function. When not in a script or function, the value substituted is not guaranteed to be meaningful. When in a function, the value is not the number of the source line that the command appears on (that information has been lost by the time the function is executed), but is an approximation of the number of simple commands executed in the current function. If LINENO is unset, it loses its special properties, even if it is subsequently reset. [40]
If this parameter is set to a filename and the MAILPATH variable is not set, bash informs the user of the arrival of mail in the specified file. [40]
Specifies how often (in seconds) bash checks for mail. The default is 60 seconds. When it is time to check for mail, the shell does so before prompting. If this variable is unset, the shell disables mail checking. [40]
A colon-separated list of pathnames to be checked for mail. The message to be printed may be specified by separating the pathname from the message with a '?'. $_ stands for the name of the current mailfile. Example: MAILPATH='/usr/spool/mail/bfox?"You have mail":~/shell-mail?"$_ has mail!"' Bash supplies a default value for this variable, but the location of the user mail files that it uses is system dependent (e.g., /usr/spool/mail/$USER). [40]
If set, and a file that bash is checking for mail has been accessed since the last time it was checked, the message 'The mail in mailfile has been read'' is printed. [40]
The previous working directory as set by the cd command. [40]
Automatically set to a string that describes the operating system on which bash is executing. The default is system-dependent. [40]
The search path for commands. It is a colon-separated list of directories in which the shell looks for commands (see COMMAND EXECUTION below). The default path is system-dependent, and is set by the administrator who installs bash. A common value is '/usr/gnu/bin:/usr/local/bin:/usr/ucb:/bin:/usr/bin:.''. [40]
The shell looks for commands and programs in a list of file paths stored in the PATH environment variable. An environment variable stores information in a place where other programs and commands can access it. Environment variables store information such as the shell that you are using, your login name, and your current working directory. To see a list of all the environment variables currently defined; type 'set' at the prompt. When you type a command at the shell prompt, the shell will look for that command's program file in each directory listed in the PATH variable, in order. The first program found matching the command you typed will be run. If the command's program file is not in a directory listed in you PATH environment variable, the shell returns a "commands not found" error. By default, the shell does not look in your current working directory or your home directory for commands This is really a security mechanism so that you don't execute programs by accident. What if a malicious user put a harmful program called ls in your home directory? If you typed ls and the shell looked for the fake program in your home directory before the real program in the /bin directory, what do you think woul dhappen? If you thought bad things, you are on the right track. Since your PATH doesn't have the current directory as one of its search locations, programs in your current directory must be called with an absolute path of a relative path specified as './program-name'. To see what directories are part of your PATH enter this command: # echo $PATH /usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/bin/X11 [66]
If set, the value is executed as a command prior to issuing each primary prompt. [40]
The value of this parameter is expanded (see PROMPTING below) and used as the primary prompt string. The default value is 'bash\$ ''. [40]
The value of this parameter is expanded and used as the secondary prompt string. The default is '> ''. [40]
The value of this parameter is used as the prompt for the select command (see SHELL GRAMMAR above). [40]
The value of this parameter is expanded and the value is printed before each command bash displays during an execution trace. The first character of PS4 is replicated multiple times, as necessary, to indicate multiple levels of indirection. The default is '+ ''. [40]
The current working directory as set by the cd command. [40]
Each time this parameter is referenced, a random integer is generated. The sequence of random numbers may be initialized by assigning a value to RANDOM. If RANDOM is unset, it loses its special properties, even if it is subsequently reset. [40]
Each time this parameter is referenced, the number of seconds since shell invocation is returned. If a value is assigned to SECONDS. the value returned upon subsequent references is the number of seconds since the assignment plus the value assigned. If SECONDS is unset, it loses its special properties, even if it is subsequently reset. [40]
Incremented by one each time an instance of bash is started. [40]
and higher A method of numbering picture files for a roll of film that has been scanned for computer presentation [34]
Used by OS/2 to keep track of archived files [34]
native format [34]
Data file (GEOWorks) [34]
Used to number old (backup) versions of files (for example, CONFIG.SYS when changed by an installation program); also used to number [34]
Database index files used by (Superbase) [34]
Backup file (Iomega Backup) [34]
Backup data file (Iomega Backup) [34]
Lotus 123 97 file [34]
Smartmaster file (Lotus 1-2-3 '97) [34]
Documenting wizard list (Microsoft Visual FoxPro) [34]
Two-dimensional drawing file (VersaCAD) (http://www.versacad.com/vcadhome.htm) [34]
and 3GR VGA Graphics driver/configuration files (Microsoft Windows) [34]
A file for use in an 80386 or higher microprocessor [34]
Three-dimensional drawing file (VersaCAD) (http://www.versacad.com/vcadhome.htm) [34]
3D NURBS modeler, (Rhino) [34]
A file in 3D Studio (for DOS) format [34]
Data file (Used by digital cameras) [34]
Compiled code (Informix 4GL) [34]
Source code (Informix 4GL) [34]
Music file (Quartet) [34]
Music mod file (Composer 669)(Unis Composer) [34]
Tracker module (Composer 669) [34]
Source file (Assembly) (Similar to Microsoft Assembler) [34]
Screen files used in the installation and instruction on use of such applications as Microsoft Codeview for C [34]
Archive. lib*.a is a static library. [40]
Library file (Unix) [34]
Object code library [34]
Authorware 3.x library [34]
Authorware MacIntosh file (unpackaged) [34]
Authorware Windows file (unpackaged) [34]
Authorware 4.x library [34]
Authorware MacIntosh file (unpackaged) [34]
Authorware file (packaged without runtime) [34]
Authorware Windows file (unpackaged) [34]
Authorware 5.x library [34]
Authorware Windows file (unpackaged) [34]
Audible audio file (commonly used for downloadable audio books) [34]
Authorware shocked file [34]
Authorware shocked packet [34]
Applix Builder file [34]
Adobe Binary Screen Font [34]
Backup file (PrintMaster Gold) [34]
Corel Draw AutoBackup [34]
Audio album file (HitPlayer) [34]
Applix Builder Turbo file [34]
MPEG Audio Sound file [34]
Sometimes used to denote an abstract (as in an abstract or summary of a scientific paper) AutoBackup [34]
Standard GNU compiler output file for a PC platform [34]
HTTP animation file (Microsoft Agent) [34]
Project Manager Workbench file [34]
ACBM Graphic image [34]
DR-DOS Viewmax file [34]
Character definiton file (Microsoft Agent) [34]
ACE Archiver Compression <http://searchStorage.techtarget.com/sDefinition/0,,sid5_gci211828,00.html> file [34]
HTTP character file (Microsoft Agent) [34]
ACI development appraisal (ACIWEB) [34]
Corel Draw 6 keyboard accelerator file [34]
Dynamic Link Library (DLL) [34]
Interplay compressed sound file (Fallout 1,2, Baulder's Gate) [34]
Windows system directory file [34]
Microsoft Office Assistant Preview file [34]
American College of Radiology file [34]
Character structered storage file (Microsoft Agent) [34]
Action Presentation [34]
Documenting wizard action diagram (Microsoft Visual FoxPro) [34]
FoxPro Foxdoc Action Diagram [34]
Microsoft Office Assistant Actor file [34]
Used to Compress and decompress audio data [34]
After Dark screensaver [34]
<http://search390.techtarget.com/sDefinition/0,,sid10_gci211523,00.html> Ada source text file (non-GNAT) [34]
Ada source text body file (GNAT) [34]
HP 100LX Organizer Appointment database [34]
Scanstudio 16 color Bitmap Graphic file [34]
OS/2 adapter driver file used in the boot process [34]
Amiga <http://WhatIs.techtarget.com/definition/0,,sid9_gci211557,00.html> disk file [34]
AutoCAD device-independent binary plotter file [34]
QEMM Mca adaptor description library [34]
After Dark MultiModule screensaver (Microsoft) [34]
Windows NT <http://searchWin2000.techtarget.com/sDefinition/0,,sid1_gci213368,00.html> policy template [34]
Lotus 1-2-3 Add-In file [34]
Astound Dynamite file [34]
Dynamic Page file (AOLserver) [34]
FaxWorks Faxmodem setup file [34]
After Dark Randomizer screensaver [34]
Smart Address address book [34]
Ada source text specification file (GNAT) [34]
AdTech Fax file [34]
HP NewWave datafile for card applications [34]
Archetype Designer Document [34]
Dynazip Active Delivery script [34]
Lotus Approach dBase Index [34]
Packed ADF file (Extracts with WinZip) [34]
Author/Editor file (SoftQuad) [34]
ArcExplorer project file [34]
ABC FlowCharter 2.0 Flowchart [34]
ABC Flowchart [34]
Apple Sound file [34]
Truevision Bitmap graphic [34]
Adobe metrics [34]
HP NewWave Cardfile application [34]
Applix graphic [34]
Adobe Illustrator drawing [34]
Corel Trace drawing [34]
Audio Interchange File, a sound format used by Silicon Graphics and Macintosh applications [34]
Similar to AIF (compressed) [34]
<http://WhatIs.techtarget.com/definition/0,,sid9_gci213472,00.html> Similar to AIF [34]
AOL Instant Messenger Launch file [34]
AIN Compressed archive [34]
APL transfer file [34]
ACDSee Image Sequence [34]
Velvet Studio Instruments file [34]
Xerox Arry of Intensity Samples Graphic [34]
HP NewWave Cardfile Application data [34]
Contains all A-keywords in the RoboHELP Help Project Index Designer not associated with topics [34]
European Telephony audio [34]
JASC Image Commander album [34]
Document file (SAP proprietary format) [34]
Alias Image [34]
X Window System font alias catalog. [40]
Arts & Letters Library [34]
WordPerfect for Windows General printer information file [34]
Alias Image [34]
WordPerfect Library Menu [34]
Applix SHELF Macro [34]
DSMIA/Asylum module music (Crusader,No Remorse,Aladdin) [34]
Music file (Advanced Module Format) [34]
ACTOR System image [34]
AMGC Compressed archive [34]
Annotation file (Cocreate SolidDesigner) [34]
Extreme's Tracker module [34]
Velvet Studio music module (MOD) file [34]
Text file (Sterling Software) (Groundworks COOL Business Team Model) [34]
Canon Computer Pattern Maker file that is a selectable list of [34]
Microsoft Windows Animated cursor [34]
DeluxPaint Animation [34]
Windows 3.x Help annotation [34]
ANSI <http://searchCIO.techtarget.com/sDefinition/0,,sid19_gci213776,00.html> Text file [34]
SimAnt for Windows saved game [34]
Nokia 9000 Add-on software [34]
Applicatio binary object template file (ZenWorks snAPPshot) [34]
Applix Presents file [34]
WHAP Compressed Amiga archive [34]
Compiled application file (Centura Team Developer) [34]
Lotus 1-2-3 Printer driver [34]
Dynamic application library file (Centura Team Developer) [34]
Lotus 1-2-3 Printer driver [34]
Lotus 1-2-3 Printer driver [34]
Project file (Allaire) (Created by Homesite) [34]
Application Program Interface; used by Adobe Acrobat <http://searchCIO.techtarget.com/sDefinition/0,,sid19_gci211517,00.html> [34]
Lotus 1-2-3 Printer driver [34]
APL Workspace file [34]
Application library file (Centura Team Developer) [34]
dBase Application Generator Object [34]
DR-DOS Executable Application [34]
FoxPro Generated Application [34]
Generated application or active document (Microsoft Visual FoxPro) [34]
Normal mode application file (Centura Team Developer) [34]
Symphony Add-in Application [34]
ArcView project file [34]
Employee Appraiser Performance Review file [34]
Lotus Approach 97 View file [34]
Advanced patching systems with error checking, (Similar to IPS) [34]
Microsoft Visual C++ file [34]
Lotus Approach Data view file [34]
Text mode application file (Centura Team Developer) [34]
Borland C++ Appexpert database [34]
Lotus Approach Paradox-Specific information file [34]
Applix data [34]
LH ARC (old version) compressed archive [34]
SQUASH Compressed archive [34]
Automatic Response file [34]
ARI Compressed archive [34]
Aristotle audio file [34]
Robert Jung ARJ compressed archive (ARJ) [34]
ARC File Archiver CPM/Port archive [34]
AOL v4.0 organizer file [34]
Atari Cubase Arrangement [34]
AOL Image file compressed using the Johson-Grace compression algorithm [34]
Canon Crayola art [34]
Clip Art [34]
First Publisher Raster graphic [34]
Ray Tracer file [34]
Xara Studio drawing [34]
ARX Compressed Archive [34]
Applix Spreadsheet [34]
Microsoft Visual InterDev <http://searchDatabase.techtarget.com/sDefinition/0,,sid13_gci213682,00.html> file [34]
ASCII <http://WhatIs.techtarget.com/definition/0,,sid9_gci211600,00.html> text file [34]
PGP <http://searchSecurity.techtarget.com/sDefinition/0,,sid14_gci214292,00.html> armored encrypted <encrypti.htm> file [34]
Astound Presentation [34]
Lotus 1-2-3 Screen driver [34]
Microsoft Advanced Streaming Format (ASF) description file; opens [34]
WinWord AutoSave file [34]
Velvet Studio Sample file [34]
Lotus 1-2-3 Screen font [34]
Microsoft Advanced Streaming Format [34]
Music file (Electronic Arts) [34]
StratGraphics Datafile [34]
TASM 3.0 Assembly language header [34]
Borland C++/Turbo C Assembler Include file [34]
Assembler <http://search390.techtarget.com/sDefinition/0,,sid10_gci211604,00.html> Language source file [34]
Pro/E assembly file [34]
Astound Dynamite Object [34]
<http://searchWin2000.techtarget.com/sDefinition/0,,sid1_gci213787,00.html> Active Server Page (an HTML file containing a Microsoft server-processed script) [34]
Astound Presentation [34]
Procomm Plus setup and connection script [34]
Astound multimedia file [34]
Claris Works "assistant" file [34]
DataCAD Autosave file [34]
Cheyenne Backup script [34]
Microsoft Advanced Streaming Redirector file [34]
Video file [34]
Aldus Persuasion 2.0 Auto Template [34]
Adobe Type Manager data/info file [34]
AT&T Group 4 bitmap [34]
AnyTime Deluxe for Windows personal information manager file from [34]
Audio format (original Sun Microsystems generic sound file). [40]
Audio U-law (pronounced mu-law) [34]
Sun/NeXT/DEC/UNIX sound file [34]
Audio file (Westwood Studios) (Kyrandia 3,C&C,RedAlert,C&C:TS) [34]
ChiWriter Auxilliary Dictionary file [34]
TeX/LaTeX Auxilliary Reference file [34]
Avagio Publication [34]
Inculan Anti-Virus virus infected file [34]
Microsoft Audio Video Interleaved file for Windows movie [34]
Video format. [40]
Audio Visual Research file [34]
Application Visualization System file [34]
Stardent AVS-X Image [34]
File Extension (ArcView) [34]
Applix Words file [34]
HP AdvanceWrite Text file [34]
FaxView Document image [34]
awk program source file. [40]
AWK Script/Program [34]
Animation Works Movie [34]
Telsis file for digitally stored audio [34]
StatGraphics Data file [34]
ArcIMS XML project file [34]
ASCII application object template (ZenWorks snAPPshot) [34]
ARJ compressed file from a multi-volume archive (xx = a number from 01 to 99) [34]
Applause Batch list [34]
1st Reader Mono binary screen image [34]
Atari/Macintosh black and white graphic [34]
1st Reader Mono and color binary screen image [34]
ABC Ventura publisher printer font [34]
Helix Nuts and Bolts file [34]
Raw graphic file (Piclab Plane II) [34]
Oracle bad file [34]
Backup file [34]
Ballade Music score [34]
dBase Application Generator Horizontal menu object [34]
BASIC <http://searchVB.techtarget.com/sDefinition/0,,sid8_gci213805,00.html> source code [34]
Batch file <http://searchWin2000.techtarget.com/sDefinition/0,,sid1_gci211642,00.html> [34]
Papyrus Database backup [34]
TeX/BibTeX Bibliographic reference file [34]
Deluxe Paint Bitmap image [34]
Bulletin Board Sytem text [34]
Batch Process Object (dBase Application Generator) [34]
Datalex Entry Point 90 Data file [34]
Microsoft Works Communications file [34]
Bitstream Outline font description file [34]
Borland C++ Makefile [34]
Borland C++ 4.5 Environment settings file [34]
Microsoft Works Dababase file [34]
Egret Datafile [34]
West Point Bridge Designer file [34]
Microsoft Publisher Border [34]
Bitstream Outline font description [34]
Bradford 2 Font [34]
Windows 95 Briefcase Document [34]
Font Metrics file (Unix/Mainframe) [34]
Fax document file (BitFax) [34]
Microsoft Backgammon Game file [34]
OS/2 Graphic array [34]
Borland Graphics Interface Driver [34]
Microsoft Flight Simulator Scenery file [34]
pcAnywhere Host file [34]
Binary <http://WhatIs.techtarget.com/definition/0,,sid9_gci211661,00.html> file [34]
Bibliography file (ASCII) [34]
bibtex LATEX bibliography source file. [40]
Database [34]
TeX/BibTeX Literature Database [34]
GroupWise initialization file [34]
Image Capture Board Binary Image black & white graphic [34]
XLITE 3D file [34]
Binary <http://WhatIs.techtarget.com/definition/0,,sid9_gci211661,00.html> file [34]
OS/2 Bios file [34]
X11 Bitmap [34]
Backup file (Generic) [34]
JetFax Faxbook file [34]
WordPerfect for Windows Document backup [34]
Backup file (Generic) [34]
WordPerfect for Windows Timed backup file for document window 1 [34]
WordPerfect for Windows Timed backup file for document window 2 [34]
WordPerfect for Windows Timed backup file for document window 3 [34]
WordPerfect for Windows Timed backup file for document window 4 [34]
WordPerfect for Windows Timed backup file for document window 5 [34]
WordPerfect for Windows Timed backup file for document window 6 [34]
WordPerfect for Windows Timed backup file for document window 7 [34]
WordPerfect for Windows Timed backup file for document window 8 [34]
WordPerfect for Windows Timed backup file for document window 9 [34]
TurboVidion Dialog Designer Backup [34]
IBM BookManager Read bookshelf file [34]
Microsoft Works Spreadsheet Backup [34]
FontEdit Fontset mirror image [34]
Resource archive (DreamWorks),(Neverhood) [34]
BASIC Bloadable picture file [34]
Alias Wavefront Image [34]
WordPerfect for Windows Temporary file [34]
Windows system Bitmap [34]
Apogee BioMenace data [34]
Corel Gallery file [34]
Windows Help bookmark [34]
Microsoft Bitmap file image format. [40]
Windows or OS/2 bitmap [34]
Instrument bank file (AdLib) [34]
Instrument Bank file (AdLib) [34]
Sound effects bank file (Electronic Arts) [34]
Compressed archive library file (Microsoft Booasm.arc) [34]
Bill of materials file (Orcad Schematic Capture) [34]
Microsoft Booasm.arc Compressed archive [34]
Adobe FrameMaker Book [34]
Lotus Notes file [34]
Business Plan Toolkit Chart [34]
Borland Delphi 4 packed library [34]
Microsoft Works Document [34]
CorelDraw Bitmap fills file [34]
Truevision Targa Bitmap [34]
BrioQuery file [34]
Bridge Script [34]
Eagle Layout file [34]
Brooktrout Fax-Mail file [34]
Application file associated with financial institution(s) loan applications [34]
A file for browsing an index of multimedia options [34]