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HP OpenVMS RTL Library (LIB$) Manual

HP OpenVMS RTL Library (LIB$) Manual


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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.

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

SS$_NORMAL Routine successfully completed.
LIB$_STRTRU Routine successfully completed. Characters are truncated in the output buffer pointed to by output-buffer.
LIB$_INVARG Invalid argument:
  • nodename is invalid.
  • nodename points to a null string.
  • The length of the node name is more than 1024 characters.
LIB$_INVSTRDES Invalid string descriptor.
LIB$_WRONUMARG Wrong number of arguments.

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:

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

SS$_NORMAL Routine successfully completed. The reserved operand was found and has been fixed.
SS$_ACCVIO Access violation. An argument to LIB$FIXUP_FLT or an operand of the faulting instruction could not be read or written.
SS$_RESIGNAL The signaled condition was not SS$_ROPRAND, or the reserved operand was not a floating-point value or was an element in a POLY x table.
SS$_ROPRAND Reserved operand fault. The optional argument new-operand was supplied but was itself an F-floating reserved operand.
LIB$_BADSTA Bad stack. The stack frame linkage has been corrupted since the time of the reserved operand exception.

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.

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.

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


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 
 
 
      

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:


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.

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

SS$_NORMAL Routine successfully completed.
LIB$_ABSTIMREQ Absolute time required.
LIB$_DEFFORUSE Default format used; unable to determine the desired format.
LIB$_ENGLUSED English used; unable to determine or use the specified language.
LIB$_REENTRANCY Reentrant invocation with same context variable.
LIB$_STRTRU Output string truncated.
LIB$_UNRFORCOD Unrecognized format code.

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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