|Document revision date: 30 March 2001|
The following keys recall commands:
The following keys control cursor position:
The following keys control screen display:
This chapter describes how to create and manipulate files locally, and over a TCP/IP or DECnet for OpenVMS network. This chapter includes information about:
For additional information, refer to the following:
A file is a unit that the OpenVMS operating system uses to store human-readable and machine-readable data. When you create or name a file, you must specify certain information so that the system can locate and identify the file. You do not have to include all the elements of a complete file specification (see Section 4.1.1). However, you must specify enough of the file specification so that, when combined with default components, the system can locate and identify the correct file according to the RMS facility's rules for file specification parsing. Refer to the Guide to OpenVMS File Applications for more information on how RMS applies defaults to partial file specifications.
If you are working in an environment with Extended File Specifications, refer to the OpenVMS Guide to Extended File Specifications for specific information about extended file names and the expanded character set available.
To override system defaults or to perform file operations over a network, you must provide a complete file specification. A complete file specification has the following format:
The components are as follows:
|Node||A network node or host name; applicable only to systems that support TCP/IP or DECnet. Does not apply to files stored on magnetic tape. Should not be used to specify a file on the same system that the user is logged in to.|
|Device||The name of the physical device on which the file is stored or is to be written.|
|Directory||The name of the directory that is used as a prefix for the directory component (See directory component description below.) Square brackets () or angle brackets (<>) are used to delimit root names. The last character of a root component before the closing bracket must be a period (.). The root component does not apply to files stored on magnetic tape.|
|Filename||The name of the file.|
|Filetype||By convention, identification of the structure or the type of the file. Many utilities provide a default value for a file's type, according to the convention, as a convenience.|
|Version||The version number of the file. Versions are identified by a decimal number, which is incremented by 1 each time a new version of the file is created. The system automatically assigns a version number unless you specify one.|
Use the following rules to specify the elements of a file specification:
For more details, refer to the Guide to OpenVMS File Applications.
Note that these rules differ for files in an environment with Extended File Specifications. Refer to the OpenVMS Guide to Extended File Specifications for more specific information about extended file names.
With certain commands, if you omit the file type, the system applies a default value. The following table lists some of the more common default file types used by DCL commands:
|.CLD||Command description file|
|.COM||Command procedure file|
|.DIF||Output file created by the DIFFERENCES command|
|.DIS||Distribution list file for the Mail utility|
|.EDT||Startup command file for the EDT editor|
|.EXE||Executable program image file created by the linker|
|.HLB||Help text library file|
|.HLP||Input source file for help libraries|
|.JOU||Journal file created by the EDT editor|
|.LIS||Listing file created by a language compiler or assembler; default input file for the PRINT and TYPE commands|
|.LOG||Batch job output file|
|.MAI||Mail message file|
|.MEM||Output file created by DIGITAL Standard Runoff (DSR)|
|.PS||POSTSCRIPT format file|
|.REGIS||Regis format file|
|.RNO||Input source file for DIGITAL Standard Runoff (DSR)|
|.SIX||Sixel graphic file|
|.SYS||System image file|
|.TJL||Journal file created by the DECTPU and ACL editors|
|.TLB||Text library file|
|.TPU||Command file for the EVE editor|
|.TPU$JOURNAL||Journal file created by the EVE editor|
|.TXT||Input file for text libraries or Mail utility output files|
The following table lists the default file types for some high-level language source programs:
|.ADA||Input source file for the Compaq Ada compiler|
|.BAS||Input source file for the BASIC compiler|
|.B32||Input source file for the VAX BLISS-32 compiler|
|.C||Input source file for the Compaq C compiler|
|.COB||Input source file for the VAX COBOL compiler on OpenVMS VAX systems and the Compaq COBOL compiler on OpenVMS Alpha systems|
|.FOR||Input source file for Compaq Fortran (Compaq Fortran for OpenVMS VAX systems was formerly VAX Fortran)|
|.M64||Input source file for the MACRO-64 assembler for OpenVMS Alpha|
|.MAP||Memory allocation map created by the Linker utility|
|.MAR||Input source file for the VAX MACRO assembler or the MACRO-32 Compiler for OpenVMS Alpha|
|.MLB||Macro library for the MACRO assembler|
|.MSG||Source file that specifies the text of messages|
|.OBJ||Object file created by a language compiler or assembler|
|.OLB||Object module library|
|.OPT||Options file for input to the LINK command|
|.PAS||Input source file for the Pascal compiler|
|.PLI||Input source file for the PL/I compiler|
|.STB||Symbol table file created by the Linker utility|
|.UPD||Update file of changes for a VAX MACRO source program; also input to the SUMSLP utility|
In addition to a file name and file type, every file has a version number. Version numbers are decimal numbers from 1 to 32,767 that differentiate versions of a file. When you create a file, the system assigns it the version number 1.
You can have several versions of the same file. Unless you specify a version number, the system uses the highest existing version number of that file. If you specify the version number 0, the system uses the highest existing version. When you modify a file with a command, application, or text editor (such as EVE) that creates a new version of the file, the file name remains the same but the version number is incremented by one.
Precede version numbers with a semicolon or a period. When the system displays file specifications, it displays a semicolon in front of the file version number.
You can refer to versions of a file in a relative manner by specifying a zero or a negative version number. Specifying zero locates the latest (highest numbered) version of the file. Specifying -1 locates the next-most-recent version, -2 the version before that, and so on. To locate the earliest (lowest numbered) version of a file, specify -0 as the version number. Note that you cannot create files with a version number higher than 32767. If you attempt to create a new file with a version number higher than 32767, you will receive an error message.
The /VERSION_LIMIT qualifier for the CREATE/DIRECTORY, SET DIRECTORY,
and SET FILE commands lets you control the number of versions of a
file. If you exceed the version limit, the system automatically purges
the lowest version file in excess of the limit. For example, if the
version limit is 5 and you create the sixth version of a file
(ACCOUNTS.DAT;6), the system deletes the first version of the file
(ACCOUNTS.DAT;1). To view the version limit on a file, enter the
DIRECTORY/FULL command. The version limit is listed in the
4.1.6 Network Node Names
A node is an individual computing system that is part of a computer network. If your system is part of a network, the node that you access when you log in is your local node. Other nodes in the network are remote nodes. Use a node name when you want to specify a file on a remote node.
A node specification has the following format:
Observe the following rules when entering a node name as part of a file specification:
On OpenVMS systems, you can specify node full names. However, you must have DECnet--Plus software installed for full node names to be recognized.
Valid full node names can contain up to 255 characters and can include any characters except the following:
If a full node name is enclosed in quotation marks (" "), it can contain any characters except unmatched quotation marks. Note that if there are quotation marks within the node name, the quotation marks must be doubled and the entire string, including the quotation marks, must also be enclosed in quotation marks.
Although the OpenVMS software enforces few rules on the syntax of node names, the actual set of valid node names is constrained by the DECnet software running on your system. For further information on full names, refer to the DECnet--Plus documentation. The syntax rules, including valid character codes, are described in detail in the DECnet--Plus DECdns Management Guide.
In the following example, the entire string is in quotation marks because there are quotation marks in the node name:
Other examples of valid full node names are:
With TCP/IP, unless otherwise stated, whenever you specify a host on a command line, you can use its host name, a fully qualified domain name, or its IP address. The relative name of a host is a simple name that does not include the fully qualified domain name; that is, it does not include one or more periods (.). Refer to the Digital TCP/IP Services for OpenVMS User's Guide for the TCP/IP syntax rules.
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