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Enabling the DECC$EFS_NO_DOTS_IN_DIRNAME feature logical suppresses the interpretation of a filename containing dots as a directory name. With this logical enabled, NAME.EXT is assumed to be a filename; no check is made for directory [.name^.ext].
By default, whenever getenv is called for a name not in the environ table, an attempt is made to resolve this as a logical name and, if this fails, as a DCL symbol.
With DECC$ENABLE_GETENV_CACHE enabled, once a logical name or DCL name has been successfully translated, its value is stored in a cache. When the same name is requested in a future call to getenv , the value is returned from the cache instead of reevaluating the logical name or DCL symbol.
Define DECC$ENABLE_TO_VMS_LOGNAME_CACHE to 1 to enable the cache with a 1-second life for each entry.
Define DECC$ENABLE_TO_VMS_LOGNAME_CACHE to 2 to enable the cache with a 2-second life for each entry.
Define DECC$ENABLE_TO_VMS_LOGNAME_CACHE to - 1 to enable the cache without a cache entry expiration.
For versions of OpenVMS before Version 7.3-2, DECC$EXEC_FILEATTR_INHERITANCE is either enabled or disabled:
For OpenVMS Version 7.3-2 and higher, DECC$EXEC_FILEATTR_INHERITANCE can be defined to 1 or 2, or be disabled:
For example, on an ODS-5 disk the OpenVMS DIRECTORY command supports a filename with the following characters:
disk:[mydir]^U65E5^U672C^U8A9E.txt |
This filename contains three UCS-2 characters (call them xxx, yyy, and zzz for typographical purposes) meaning "day", "origin", and "language", respectively.
With UTF-8 support enabled, a C program can now read the filename from the VMS directory and use that filename as an UTF-8 encoded string.
For example, opendir("/disk/mydir") followed by a readdir will place the following into the d_name field of the supplied dirent structure:
"\xE6\x97\xA5\xE6\x9C\xAC\xE8\xAA\x9E.txt" |
One of the following calls can then open this file:
open("/disk/mydir/\xE6\x97\xA5\xE6\x9C\xAC\xE8\xAA\x9E.txt",O_RDWR,0) open("/disk/mydir/xxxyyyzzz.txt", O_RDWR,0) |
The "\xE6\x97\xA5" above is the byte stream E697A5, which represents the xxx character in UTF-8 encoding. See the following example, where the actual characters comprising the filename are shown:
Figure 1-2 Unicode Example
This feature enhances the UNIX portability of international software that uses UTF-8 encoded filenames.
The DECC$FILENAME_ENCODING_UTF8 feature logical controls whether or not the C RTL allows and correctly interprets Unicode UTF-8 encoding for filenames given in UNIX style.
This logical is undefined by default, and the C RTL behavior is to accept filenames as ASCII and Latin-1 format.
This feature works only on ODS-5 disks. Therefore, to enable Unicode UTF-8 encoding, you must define both the DECC$FILENAME_ENCODING_UTF8 and DECC$EFS_CHARSET logicals to ENABLE.
: [ ^ |
With DECC$FILENAME_UNIX_NO_VERSION disabled, in UNIX style names, version numbers are reported preceded by a period (.).
With DECC$FILENAME_UNIX_REPORT disabled, unless specified in the function call, filenames are reported in OpenVMS style.
With DECC$FILE_PERMISSION_UNIX disabled, modes 0 and 0777 indicate using RMS default protection or protection from the previous version of the file. Permissions for new directories also follow OpenVMS rules, including disabling DELETE permissions.
With DECC$FIXED_LENGTH_SEEK_TO_EOF disabled, lseek , fseek , and fseeko when called with SEEK_EOF on files with fixed-length records, will position relative to the end of the last record in the file.
Default: 0
Maximum: 2147483647
With DECC$MAILBOX_CTX_STM enabled, the record attribute FAB$M_CR is not set.
The preceding three cases lead to predictable, expected results.
In the case where the first element is a search list that consists of a mixture of rooted and nonrooted logicals, translating paths as described previously can lead to different behavior from that of older versions of OpenVMS (before OpenVMS Version 7.3-1):
DECC$NO_ROOTED_SEARCH_LISTS controls how the decc$to_vms function resolves search-list logicals and provides a means to restore the OpenVMS behavior prior to Version 7.3-1.
With DECC$NO_ROOTED_SEARCH_LISTS enabled:
Enabling this feature logical provides the pre-Version 7.3-1 behavior for search list logicals.
With DECC$NO_ROOTED_SEARCH_LISTS disabled:
Disabling this feature logical provides the behavior for OpenVMS Version 7.3-1 and later.
DECC$PIPE_BUFFER_QUOTA lets you specify a buffer quota to use for the pipe function if the optional fourth argument of that function is omitted.
If the optional pipe fourth argument is omitted and DECC$PIPE_BUFFER_QUOTA is not defined, then the buffer quota defaults to the buffer size, as before.
Default: 512
Minimum: 512
Maximum: 2147483647
DECC$PIPE_BUFFER_SIZE allows a larger buffer size to be used for pipe functions such as pipe and popen . A value of 512 to 65535 bytes can be specified.
If DECC$PIPE_BUFFER_SIZE is not specified, the default buffer size 512 is used.
Default: 512
Minimum: 512
Maximum: 65535
With DECC$POPEN_NO_CRLF_REC_ATTR enabled, CR/LF carriage control is prevented from being added to the pipe records. This is compatible with UNIX behavior, but be aware that enabling this feature might result in undesired behavior from other functions, such as gets , that rely on the carriage-return character.
By default DECC$POSIX_COMPLIANT_PATHNAMES is disabled, and the usual C RTL behavior prevails. This disabled mode includes interpretation of pathnames as UNIX style specifications and uses rules that are different and unrelated to POSIX-compliant pathname processing.
To enable DECC$POSIX_COMPLIANT_PATHNAMES, set it to one of the following values:
1 | All pathnames are designated as POSIX style. |
2 | Pathnames that end in " : " or contain any of the bracket characters " []<> ", and that can be successfully parsed by the SYS$FILESCAN service, are designated as OpenVMS style. Otherwise, they are designated as POSIX style. |
3 | The pathnames " . " and " .. ", or pathnames that contain " / " are designated as POSIX style. Otherwise, they are designated as OpenVMS style. |
4 | All pathnames are designated as OpenVMS style. |
See Section 12.3.1 for more information.
With DECC$POSIX_SEEK_STREAM_FILE disabled, positioning beyond end-of-file will immediately write zeros to the file from the current end-of-file to the new position.
With this logical name disabled, UIDs and GIDs are derived from the process UIC.
This feature is only available on OpenVMS systems providing POSIX style UID and GID support.
With this logical name disabled, all files without a file type are reported with a trailing period.
With DECC$READDIR_KEEPDOTDIR enabled, directories are reported in UNIX style with a file type of ".DIR".
With this logical name disabled, you get the expected OpenVMS behavior. For example:
Renaming "A.A" to "B" yields "B.A"
rename("file.ext", "logical_name") /* where logical_name = dev:[dir.subdir] */ /* and :[dir.subdir] exists. */ |
This results in:
dev:[dir.subdir]file.ext |
This example renames a file from one directory into another directory, which is the same behavior as in legacy versions of OpenVMS (versions before 7.3-1). Also in this example, if dev:[dir.subdir] does not exist, rename returns an error.
Disabling DECC$RENAME_ALLOW_DIR provides a more UNIX compliant conversion of the "logical_name" argument of rename . Consider the following example with DECC$RENAME_ALLOW_DIR disabled:
rename("file.ext", "logical_name") /* where logical_name = dev:[dir.subdir] */ |
This results in:
dev:[dir]subdir.ext |
This example renames the file using the subdir part of the "logical_name" argument as the new filename because on UNIX systems, renaming a file to a directory is not allowed. So rename internally converts the "logical_name" to a filename, and dev:[dir]subdir is the most reasonable conversion it can perform.
This new feature switch has a side effect of causing rename to a directory to take precedence over rename to a file. Consider this example:
rename ( "file1.ext", "dir2" ) /* dir2 is not a logical */ |
With DECC$RENAME_ALLOW_DIR disabled, this example results in dir2.ext , regardless of whether or not subdirectory [.dir2] exists.
With DECC$RENAME_ALLOW_DIR enabled, this example results in dir2.ext only if subdirectory [.dir2] does not exist. If subdirectory [.dir2] does exist, the result is [.dir2]file1.ext .
If DECC$RENAME_NO_INHERIT is enabled, UNIX compliant behavior is expected, so DECC$RENAME_ALLOW_DIR is ignored, and renaming a file to a directory is not allowed. |
With DECC$SELECT_IGNORES_INVALID_FD disabled, select ignores invalid file descriptors.
With DECC$STDIO_CTX_EOL disabled, each fwrite generates a separate write, which for mailbox and record files generates a separate record.
With DECC$STREAM_PIPE disabled, pipe uses the OpenVMS legacy record I/O. This is the default.
With DECC$STRTOL_ERANGE disabled, the legacy behavior of leaving the pointer at the failing digit is preserved.
The alternate mode protects thread-specific data only if another function has it locked. This protects data that is in use within the C RTL, but does not protect the caller from an AST changing the data pointed to.
This latter mode is now the C RTL default for the strtok , ecvt , and fcvt functions.
You can select the legacy AST safe mode by enabling DECC$THREAD_DATA_AST_SAFE.
Default: 2
Maximum: 2147483647
To enter the value as an octal value, add the leading zero; otherwise, it is translated as a decimal value. For example:
$ DEFINE DECC$UMASK 026 |
Maximum: 0777
The principal logical names affecting UNIX like behavior are grouped as follows:
1 General corrections
10 Enhancements
20 UNIX style filenames
30 UNIX style file attributes
90 Full UNIX behavior - No concessions to OpenVMS
Level 30 is appropriate for UNIX like programs such as BASH and GNV.
The DECC$UNIX_LEVEL values and associated groups of affected feature logical names are:
General Corrections (DECC$UNIX_LEVEL 1) DECC$FIXED_LENGTH_SEEK_TO_EOF 1 DECC$POSIX_SEEK_STREAM_FILE 1 DECC$SELECT_IGNORES_INVALID_FD 1 DECC$STRTOL_ERANGE 1 DECC$VALIDATE_SIGNAL_IN_KILL 1 General Enhancements (DECC$UNIX_LEVEL 10) DECC$ARGV_PARSE_STYLE 1 DECC$EFS_CASE_PRESERVE 1 DECC$STDIO_CTX_EOL 1 DECC$PIPE_BUFFER_SIZE 4096 DECC$USE_RAB64 1 UNIX style filenames (DECC$UNIX_LEVEL 20) DECC$DISABLE_TO_VMS_LOGNAME_TRANSLATION 1 DECC$EFS_CHARSET 1 DECC$FILENAME_UNIX_NO_VERSION 1 DECC$FILENAME_UNIX_REPORT 1 DECC$READDIR_DROPDOTNOTYPE 1 DECC$RENAME_NO_INHERIT 1 DECC$GLOB_UNIX_STYLE UNIX like file attributes (DECC$UNIX_LEVEL 30) DECC$EFS_FILE_TIMESTAMPS 1 DECC$EXEC_FILEATTR_INHERITANCE 1 DECC$FILE_OWNER_UNIX 1 DECC$FILE_PERMISSION_UNIX 1 DECC$FILE_SHARING 1 UNIX compliant behavior (DECC$UNIX_LEVEL 90) DECC$FILENAME_UNIX_ONLY 1 DECC$POSIX_STYLE_UID 1 DECC$USE_JPI$_CREATOR 1 DECC$DETACHED_CHILD_PROCESS 1 |
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Enabling DECC$UNIX_PATH_BEFORE_LOGNAME overrides the setting for DECC$DISABLE_TO_VMS_LOGNAME_TRANSLATION.
This feature is only available on systems supporting POSIX style session identifiers.
This provides latent support for file buffers in 64-bit memory.
With this logical name disabled, validation of signals is restricted to checking that the signal value is in the range 0 to _SIG_MAX. If sys$sigprc fails, errno is set based on sys$sigprc exit status.
With DECC$V62_RECORD_GENERATION enabled, the output mechanism follows the rules used for OpenVMS Version 6.2.
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