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HP OpenVMS RTL Library (LIB$) Manual
LIB$FIT_NODENAME
The Fit a Node Name Into an Output Field routine fits a node name into
an output field. It attempts to compress the node name to fit the
output field. If this fails, it trims the node name.
Note
No support for arguments passed by 64-bit address reference or for use
of 64-bit descriptors, if applicable, is planned for this routine.
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Format
LIB$FIT_NODENAME nodename, output-buffer
[,output-width][,resultant-length]
RETURNS
| OpenVMS usage: |
cond_value |
| type: |
longword (unsigned) |
| access: |
write only |
| mechanism: |
by value |
Arguments
nodename
| OpenVMS usage: |
char_string |
| type: |
character string |
| access: |
read only |
| mechanism: |
by descriptor |
Node name to be fitted into the desired output field. The
nodename argument contains the address of a descriptor
pointing to this node-name string.
The error LIB$_INVARG is returned if nodename contains
an invalid node name, points to a null string, or contains more than
1024 characters. The error LIB$_INVSTRDES is returned if
nodename is an invalid descriptor.
output-buffer
| OpenVMS usage: |
char_string |
| type: |
character string |
| access: |
write only |
| mechanism: |
by descriptor |
The output buffer. The output-buffer argument contains
the address of a descriptor pointing to the output buffer.
LIB$FIT_NODENAME writes the final output node name into the buffer
pointed to by output-buffer.
The error LIB$_INVSTRDES is returned if output-buffer
is an invalid descriptor.
The length field of the output-buffer descriptor is
not updated unless output-buffer is a dynamic
descriptor with a length less than the resulting fitted node name.
Refer to the OpenVMS RTL String Manipulation (STR$) Manual for dynamic string descriptor usage.
The output-buffer argument contains an unusable result
when LIB$FIT_NODENAME returns in error.
output-width
| OpenVMS usage: |
word_unsigned |
| type: |
word (unsigned) |
| access: |
read only |
| mechanism: |
by reference |
Field width desired for the fit operation. The
output-width argument is the address of an unsigned
word that contains this field width in bytes.
If output-width is omitted, the current length of
output-buffer is used. If
output-buffer is not a fixed-length string, specify
output-width to ensure that the desired width is used.
If the lengths of both output-buffer and
output-width are specified, the length in
output-width is used. In this case, if the current
length of output-buffer is smaller than the length of
output-width, the output node name is truncated at the
end, and the alternate successful status LIB$_STRTRU is returned.
resultant-length
| OpenVMS usage: |
word_unsigned |
| type: |
word (unsigned) |
| access: |
write only |
| mechanism: |
by reference |
Length of the output node name. The resultant-length
argument is the address of an unsigned word that contains this length
in bytes.
The resultant-length argument contains an unusable
result when LIB$FIT_NODENAME returns in error.
Description
This routine fits the input node name into the desired output field for
display purposes. It first attempts to get the usable short form of the
input node name by calling LIB$COMPRESS_NODENAME. If that fails, the
input node name is expanded by LIB$EXPAND_NODENAME and then trimmed by
LIB$TRIM_FULLNAME to fit the desired output width.
The input is validated against the supported form of input node names.
The error LIB$_INVARG is returned if the input node name is invalid.
Node-name compression is always attempted even if the length of the
input node name is less than or equal to the desired output width. This
is to ensure that the short form of a full name is always chosen for
display purposes.
When the compressed node name is too long to fit the desired output
width, the input node name is expanded using LIB$EXPAND_NODENAME and
trimmed using LIB$TRIM_FULLNAME. In this case, the alternate success
status LIB$_STRTRU is returned.
When LIB$FIT_NODENAME encounters errors from the underlying network
services, it tries to return the string-truncated compressed node name.
If it is the compression operation that fails, LIB$FIT_NODENAME returns
the string-truncated input node name. The alternate successful status
LIB$_STRTRU is returned.
Note that the returned node name can be either a compressed usable
short form of the input node name or an unusable trimmed or truncated
node name. The caller should always assume an unusable node name is
returned when it finds the alternate success return status LIB$_STRTRU.
On the other hand, the SS$_NORMAL return status means that a usable
form of a node name is returned.
LIB$FIT_NODENAME adds padding spaces to the end of the output buffer if
the output node name is shorter than the size of the output buffer. The
argument resultant-length, if supplied, is set to the
length of the output node name, excluding any padding spaces.
Condition Values Returned
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SS$_NORMAL
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Routine successfully completed.
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LIB$_STRTRU
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Routine successfully completed. Characters are truncated in the output
buffer pointed to by
output-buffer.
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LIB$_INVARG
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Invalid argument:
-
nodename is invalid.
-
nodename points to a null string.
- The length of the node name is more than 1024 characters.
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LIB$_INVSTRDES
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Invalid string descriptor.
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LIB$_WRONUMARG
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Wrong number of arguments.
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Any condition value returned by LIB$SCOPY_R_DX.
LIB$FIXUP_FLT
The Fix Floating Reserved Operand routine finds the reserved operand of
any F-floating, D-floating, G-floating, or H-floating instruction (with
some exceptions) after a reserved operand fault has been signaled.+
LIB$FIXUP_FLT changes the reserved operand from --0.0 to the value of
the new-operand argument, if present; or to +0.0 if
new-operand is absent.
This routine is available on OpenVMS Alpha and I64 systems in
translated form and is applicable to translated VAX images only.
Format
LIB$FIXUP_FLT signal-arguments ,mechanism-arguments [,new-operand]
RETURNS
| OpenVMS usage: |
cond_value |
| type: |
longword (unsigned) |
| access: |
write only |
| mechanism: |
by value |
Arguments
signal-arguments
| OpenVMS usage: |
vector_longword_unsigned |
| type: |
unspecified |
| access: |
read only |
| mechanism: |
by reference, array reference |
Signal argument vector. The signal-arguments argument
is the address of an array of unsigned longwords containing the signal
argument vector.
mechanism-arguments
| OpenVMS usage: |
vector_longword_unsigned |
| type: |
unspecified |
| access: |
read only |
| mechanism: |
by reference, array reference |
Mechanism argument vector. The mechanism-arguments
argument is the address of an array of unsigned longwords containing
the mechanism argument vector.
new-operand
| OpenVMS usage: |
floating-point |
| type: |
F_floating |
| access: |
read only |
| mechanism: |
by reference |
An F-floating value to replace the reserved operand. The
new-operand argument is the address of an F-floating
number containing the new operand. This is an optional argument. If
omitted, the default value is +0.0.
Description
LIB$FIXUP_FLT finds the reserved operand of any F-floating, D-floating,
G-floating, or H-floating instruction (with some exceptions) after a
reserved operand fault has been signaled. LIB$FIXUP_FLT changes the
reserved operand from --0.0 to the value of the
new-operand argument, if present; or to +0.0 if
new-operand is absent. LIB$FIXUP_FLT cannot handle the
following cases and will return a status of SS$_RESIGNAL if any of them
occur:
- The currently active signaled condition is not SS$_ROPRAND.
- The reserved operand's data type is not F-floating, D-floating,
G-floating, or H-floating.
- The reserved operand is an element in the coefficient table for one
of the VAX POLYx instructions.
If the status value returned from LIB$FIXUP_FLT is seen by the
condition handling facility (as would be the case if LIB$FIXUP_FLT was
the handler), any success value is equivalent to SS$_CONTINUE, which
causes the instruction to be restarted. Any failure value is equivalent
to SS$_RESIGNAL, which causes the condition to be resignaled to the
next handler. This resignal status is because the condition handler
(LIB$FIXUP_FLT) was unable to handle the condition correctly.
LIB$FIXUP_FLT can be enabled directly as a condition handler. The
signal-arguments and
mechanism-arguments arguments are passed to the
condition handler by OpenVMS exception dispatching.
Condition Values Returned
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SS$_NORMAL
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Routine successfully completed. The reserved operand was found and has
been fixed.
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SS$_ACCVIO
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Access violation. An argument to LIB$FIXUP_FLT or an operand of the
faulting instruction could not be read or written.
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SS$_RESIGNAL
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The signaled condition was not SS$_ROPRAND, or the reserved operand was
not a floating-point value or was an element in a POLY
x table.
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SS$_ROPRAND
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Reserved operand fault. The optional argument
new-operand was supplied but was itself an F-floating
reserved operand.
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LIB$_BADSTA
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Bad stack. The stack frame linkage has been corrupted since the time of
the reserved operand exception.
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Note
+ No support for arguments passed by 64-bit
address reference or for use of 64-bit descriptors, if applicable, is
planned for this routine.
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LIB$FLT_UNDER
The Floating-Point Underflow Detection routine enables or disables
floating-point underflow detection for the calling routine activation.
The previous setting is returned as a function value.
Note
No support for arguments passed by 64-bit address reference or for use
of 64-bit descriptors, if applicable, is planned for this routine.
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This routine is available on OpenVMS Alpha and I64 systems in
translated form and is applicable to translated VAX images only.
Format
LIB$FLT_UNDER new-setting
RETURNS
| OpenVMS usage: |
longword_unsigned |
| type: |
longword (unsigned) |
| access: |
write only |
| mechanism: |
by value |
The old floating-point underflow enable setting (the previous contents
of the SF$W_PSW[PSW$V_FU] in the caller's frame).
Argument
new-setting
| OpenVMS usage: |
longword_unsigned |
| type: |
longword (unsigned) |
| access: |
read only |
| mechanism: |
by reference |
New floating-point underflow enable setting. The
new-setting argument is the address of an unsigned
byte containing the new setting. Bit 0 set to 1 means enable; bit 0 set
to 0 means disable.
Description
LIB$FLT_UNDER affects only the current routine activation and does not
affect any of its callers or any routines that it may call. However,
the setting does remain in effect for any routines entered through a
JSB entry point.
The caller's stack frame will be modified by this routine.
Condition Values Returned
None.
Example
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C+
C This Fortran example program shows
C the use of LIB$FLT_UNDER.
C-
INTEGER*4 NEW_SETTING
REAL*4 X , Y , Z
NEW_SETTING = 0
X = 1E-20
Y = 1E20
CALL LIB$FLT_UNDER( NEW_SETTING )
TYPE *,'First Case: This should not have an underflow exception'
Z = X / Y
TYPE *, 'If this lines prints then the underflow exception
1 was disabled.'
TYPE *
NEW_SETTING = 1
X = 1E-20
Y = 1E20
CALL LIB$FLT_UNDER( NEW_SETTING )
TYPE * , 'Second Case: This should have an underflow exception
1 and then stop.'
Z = X / Y
TYPE * , 'If this line prints, then the underflow exception
1 was disabled.'
END
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In this Fortran example, floating-point underflow detection is disabled
the first time X is divided by Y. The second time, underflow detection
is enabled, and the program stops because of the error generated.
LIB$FORMAT_DATE_TIME
The Format Date and/or Time routine allows the user to select at run
time a specific output language and format for a date or time, or both.
Format
LIB$FORMAT_DATE_TIME date-string [,date] [,user-context] [,date-length]
[,flags]
RETURNS
| OpenVMS usage: |
cond_value |
| type: |
longword (unsigned) |
| access: |
write only |
| mechanism: |
by value |
Arguments
date-string
| OpenVMS usage: |
char_string |
| type: |
character string |
| access: |
write only |
| mechanism: |
by descriptor |
Receives the requested date or time, or both, that has been formatted
for output according to the currently selected format and language. The
date-string argument is the address of a descriptor
pointing to this string.
date
| OpenVMS usage: |
date_time |
| type: |
quadword (unsigned) |
| access: |
read only |
| mechanism: |
by reference |
The date or time, or both, to be formatted for output. The
date argument is the address of an unsigned quadword
that contains the absolute date or time, or both to be formatted. If
you omit this argument, or if you supply a zero passed by value, then
the current system time is used. Note that the date
argument must represent an absolute time, not a delta time.
user-context
| OpenVMS usage: |
context |
| type: |
longword (unsigned) |
| access: |
modify |
| mechanism: |
by reference |
User context that retains the translation context over multiple calls
to this routine. The user-context argument is the
address of an unsigned longword that contains this context. The initial
value of the context variable must be zero. Thereafter, the user
program must not write to the cell.
The user-context parameter is optional. However, if a
context cell is not passed, the routine LIB$FORMAT_DATE_TIME may abort
if two threads of execution attempt to manipulate the context area
concurrently. Therefore, when calling this routine in situations where
reentrancy might occur, such as from AST level, HP recommends that
users specify a different context cell for each calling thread.
date-length
| OpenVMS usage: |
longword_signed |
| type: |
longword (signed) |
| access: |
write only |
| mechanism: |
by reference |
Number of bytes of text written to the date-string
argument. The date-length argument is the address of a
signed longword that receives this string length. Note that
date-length specifies the number of bytes of text, not
the number of characters, written to date-string.
flags
| OpenVMS usage: |
mask_longword |
| type: |
longword (unsigned) |
| access: |
read only |
| mechanism: |
by reference |
Bit mask that allows the user to specify whether the date, time, or
both are output. The flags argument is the address of
an unsigned bit mask containing the specified values. Valid values are
LIB$M_DATE_FIELDS and LIB$M_TIME_FIELDS.
Default values are determined as follows:
- If the flags argument is omitted,
LIB$FORMAT_DATE_TIME determines which fields to format according to the
current definition of LIB$DT_FORMAT.
- If the flags argument is specified,
LIB$FORMAT_DATE_TIME uses the flags value to determine
which fields to format. That is, the flags argument
can be used to override the definition of LIB$DT_FORMAT when specifying
which fields should be formatted for output. If the field specified by
flags was not assigned a format through the definition
of LIB$DT_FORMAT, the standard OpenVMS format is used.
Description
The LIB$FORMAT_DATE_TIME routine formats an OpenVMS internal format
date-time quadword into a textual string of some predefined format. The
language to be used and the format in which to output the information
are programmable using either of the following methods.
- The language and format are programmable at compile time through
the use of the routine LIB$INIT_DATE_TIME_CONTEXT.
- The language and format are determined at run time through the
translation of the logical names SYS$LANGUAGE
and LIB$DT_FORMAT.
In general, if an application is formatting text for internal storage
or transmission, the language and format should be specified at compile
time. If this is the case, use the routine LIB$INIT_DATE_TIME_CONTEXT
to specify the language and format of your choice.
If an application is formatting text for presentation to a user, the
logical name method of specifying language and format should be used.
In this method, the user assigns equivalence names to the logical names
SYS$LANGUAGE and LIB$DT_FORMAT, thereby selecting the language and
format of the date and time at run time.
If the logical name method is used, the translations of the logical
names SYS$LANGUAGE and LIB$DT_FORMAT specify one or more executive mode
logicals, which in turn must be translated to determine the actual
format string. These additional logicals supply such things as the
names of the days of the week and the months in the selected language
(determined by SYS$LANGUAGE). All of these logicals are predefined, so
that a non-privileged user can select any one of these languages and
formats. A user can create his or her own languages and formats;
however, the CMEXEC, SYSNAME, and SYSPRV privileges are required.
With the exception of SYS$LANGUAGE and LIB$DT_FORMAT, all logical names
used by this routine must be defined from the executive mode.
See the HP OpenVMS Programming Concepts Manual for a description of system date and time
operations as well as a detailed description of the format mnemonics
used in these routines.
Condition Values Returned
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SS$_NORMAL
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Routine successfully completed.
|
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LIB$_ABSTIMREQ
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Absolute time required.
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LIB$_DEFFORUSE
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Default format used; unable to determine the desired format.
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LIB$_ENGLUSED
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English used; unable to determine or use the specified language.
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LIB$_REENTRANCY
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Reentrant invocation with same context variable.
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LIB$_STRTRU
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Output string truncated.
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LIB$_UNRFORCOD
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Unrecognized format code.
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Any condition values returned by the $NUMTIM system service, or RTL
routines LIB$GET_VM, LIB$GET_VM_64, LIB$ANALYZE_SDESC, or
LIB$ANALYZE_SDESC_64.
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