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HP OpenVMS systems documentation |
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The Revert to the Handler of the Routine Activator routine deletes the condition handler established by LIB$ESTABLISH by clearing the address pointing to the condition handler from the activated routine's stack frame.
Note
No support for arguments passed by 64-bit address reference or for use of 64-bit descriptors, if applicable, is planned for this routine.
This routine is not available to native OpenVMS Alpha and I64 programs but is recognized and handled appropriately by most HP high-level language compilers.
LIB$REVERT
OpenVMS usage: address type: address access: write only mechanism: by value
Previous contents of SF$A_HANDLER (longword 0) of the caller's stack frame. This is the address of the condition handler previously in effect. If no condition handler was in effect, zero is returned.
None.
LIB$REVERT returns the address that it clears from the calling routine's stack frame. LIB$REVERT is used only if your routine is to establish and then cancel a condition handler for a portion of its execution.LIB$REVERT is provided primarily for use with languages without built-in error-handling facilities, such as Fortran. Do not use LIB$REVERT from BASIC, COBOL, Pascal, or PL/I. See the documentation for the language you are using for information about how that language handles errors.
In VAX MACRO, you merely use the following instruction rather than calling LIB$REVERT:
CLRL (FP) ; set handler address to 0 ; in current stack frame
None.
The Run New Program routine causes the current program to stop running and begins execution of another program.
LIB$RUN_PROGRAM program-name
OpenVMS usage: cond_value type: longword (unsigned) access: write only mechanism: by value
program-name
OpenVMS usage: char_string type: character string access: read only mechanism: by descriptor
File name of the program to be run in place of the current program. The program-name argument contains the address of a descriptor pointing to this file name string.The maximum length of the file name is 255 characters. The default file type is .EXE.
LIB$RUN_PROGRAM stops execution of the current program and begins execution of another program.
- If successful, control does not return to the calling program. Instead, the $EXIT system service is called, the new program image replaces the old image in the user process, and the command language interpreter (CLI) gives control to the new image.
- If unsuccessful, control returns to the command interpreter.
This routine is supported for use with the DCL and MCR CLIs. If an image is run directly as a subprocess or as a detached process, there is no CLI present to perform this function. In those cases, the error status LIB$_NOCLI is returned.
LIB$RUN_PROGRAM causes the current image to exit at the point of the call and directs the CLI, if one is present, to start running another program. If LIB$RUN_PROGRAM executes successfully, control passes to the second program; if not, control passes to the CLI. The calling program cannot regain control. This technique is called chaining.
This routine is provided primarily for compatibility with PDP-11 systems, where chaining is used to extend the address space of a system.
This routine may also be useful in an OpenVMS environment where address space is severely limited and large images are not possible. For example, you might use chaining to perform system generation on a small virtual address space, for a large page file.
With LIB$RUN_PROGRAM, the calling program can pass arguments to the next program in the chain only by using the common storage area. One way to do this is for the calling program to call LIB$PUT_COMMON to pass the information into the common storage area. Then the called program calls LIB$GET_COMMON to retrieve the data.
In general, this practice is not recommended. There is no convenient way to specify the order and type of arguments passed into the common storage area; so programs that pass arguments in this way must know about the format of the data before it is passed. When you use common storage, it is very difficult to keep your program modular and AST-reentrant; a method of arbitration must be designated to define which program can modify common storage and when.
Further, LIB$RUN_PROGRAM cannot be used if no command language interpreter is present, as in the case of image subprocesses and detached subprocesses.
If you want control to return to the caller, use LIB$SPAWN instead.
LIB$_INVARG Invalid argument. LIB$_NOCLI No CLI present to perform function. The calling process did not have a CLI to perform the function or the CLI did not support the request type. Note that an image run as a subprocess or detached process does not have a CLI. LIB$_UNECLIERR Unexpected CLI error. The CLI returned an error status which was not recognized. This error may be caused by use of a nonstandard CLI. If this error occurs while using the DCL or MCR CLIs, please report the problem to your HP support representative.
The Scan for Characters and Return Relative Position routine is used to find a specified set of characters in the source string. LIB$SCANC makes the VAX SCANC instruction available as a callable routine.
Note
On Alpha and I64 systems, OpenVMS Alpha and I64 instructions perform the equivalent operation.
LIB$SCANC source-string ,table-array ,byte-integer-mask
OpenVMS usage: cond_value type: longword (unsigned) access: write only mechanism: by value
Relative position in the source string of the character that terminated the operation, or zero if the terminator character is not found. If the source string has a zero length, then a zero is returned.
source-string
OpenVMS usage: char_string type: character string access: read only mechanism: by descriptor
Source string used by LIB$SCANC to index into a table. The source-string argument contains the address of a descriptor pointing to this source string.table-array
OpenVMS usage: vector_mask_byte type: byte (unsigned) access: read only mechanism: by reference, array reference
Table that LIB$SCANC indexes into and performs a logical AND operation with the byte-integer-mask byte. The table-array argument contains the address of an unsigned byte array that is this table.byte-integer-mask
OpenVMS usage: mask_byte type: byte (unsigned) access: read only mechanism: by reference
Mask on which a logical AND operation is performed with bytes in table-array. The byte-integer-mask argument contains the address of an unsigned byte that is this mask.
LIB$SCANC uses successive bytes of the string specified by source-string to index into a table. The byte selected from the table is the byte on which a logical AND operation is performed with the mask byte. The operation is terminated when the result of the AND operation is equal to 1.
None.
The Copy Source String Passed by Descriptor to Destination routine copies a source string passed by descriptor to a destination string.
LIB$SCOPY_DXDX source-string ,destination-string
Corresponding JSB Entry Point
LIB$SCOPY_DXDX6
OpenVMS usage: cond_value type: longword (unsigned) access: write only mechanism: by value
source-string
OpenVMS usage: char_string type: character string access: read only mechanism: by descriptor
Source string to be copied to the destination string by LIB$SCOPY_DXDX. The source-string argument contains the address of a descriptor pointing to this source string. The descriptor class can be unspecified, fixed-length, decimal string, array, noncontiguous array, varying, or dynamic.destination-string
OpenVMS usage: char_string type: character string access: write only mechanism: by descriptor
Destination string to which the source string is copied. The destination-string argument contains the address of a descriptor pointing to this destination string.The following actions occur depending on the class of the destination string's descriptor:
Descriptor Class Action S, Z, SD, A, NCA Copy the source string. If needed, space-fill or truncate on the right. D If the area specified by the destination descriptor is large enough to contain the source string, copy the source string and set the new length in the destination descriptor. If the area specified is not large enough, return the previous space allocation (if any) and then dynamically allocate the amount of space needed. Copy the source string and set the new length and address in the destination descriptor. VS Copy source string to destination string up to the limit of the descriptor MAXSTRLEN field with no padding. Readjust the current length (CURLEN) field to the actual number of bytes copied.
LIB$SCOPY_DXDX returns all condition values as a status; truncation is a qualified success condition value (bit 0 set to 1).In addition, an equivalent JSB entry point is available, with R0 containing the first argument and R1 containing the second.
SS$_NORMAL Routine successfully completed. All characters in the input string were copied to the destination string. LIB$_STRTRU Routine successfully completed. String truncated. The destination string could not contain all of the characters copied from the source string. LIB$_FATERRLIB Fatal internal error. An internal consistency check has failed. This usually indicates an internal error in the Run-Time Library and should be reported to your HP support representative. LIB$_INSVIRMEM Insufficient virtual memory. Your program has exceeded the image quota for virtual memory. LIB$_INVSTRDES Invalid string descriptor. A string descriptor has an invalid value in its CLASS field.
The Copy Source String Passed by Reference to Destination String routine copies a source string passed by reference to a destination string, passed by descriptor.
LIB$SCOPY_R_DX word-integer-source-length ,source-string ,destination-string
Corresponding JSB Entry Point
LIB$SCOPY_R_DX6
OpenVMS usage: cond_value type: longword (unsigned) access: write only mechanism: by value
word-integer-source-length
OpenVMS usage: word_unsigned type: word (unsigned) access: read only mechanism: by reference
Length of the source string in bytes. The word-integer-source-length argument is the address of an unsigned word that contains the length of the source string.source-string
OpenVMS usage: char_string type: character string access: read only mechanism: by reference
Source string to be copied to the destination string by LIB$SCOPY_R_DX. The source-string argument is the address of this source string.destination-string
OpenVMS usage: char_string type: character string access: write only mechanism: by descriptor
Destination string to which the source string is copied. The destination-string argument contains the address of a descriptor pointing to this destination string.
LIB$SCOPY_R_DX copies a source string, passed by reference, to a destination string, passed by descriptor. It returns the status as a condition value. Truncation is a qualified success; LIB$SCOPY_R_DX sets bit 0 of the condition value to 1.The actions taken by LIB$SCOPY_R_DX depend on the descriptor class of the destination string. The following table describes these actions for each descriptor class:
Descriptor Class Action S, Z, SD, A, NCA Copy the source string. If needed, space fill or truncate on the right. D If the area specified by the destination descriptor is large enough to contain the source string, copy the source string and set the new length in the destination descriptor. If the area specified is not large enough, return the previous space allocation, if any, and then dynamically allocate the amount of space needed. Copy the source string and set the new length and address in the destination descriptor. VS Copy source string to destination string up to the limit of the decsriptor's MAXSTRLEN field with no padding. Readjust the string's current length (CURLEN) field to the actual number of bytes copied. An equivalent JSB entry is available, with R0 being the first argument, R1 the second, and R2 the third. The length argument is passed in bits 15:0 of R0.
SS$_NORMAL Routine successfully completed. All characters in the input string were copied to the destination string. LIB$_STRTRU Routine successfully completed. String truncated. The destination string could not contain all of the characters copied from the source string. LIB$_FATERRLIB Fatal internal error. An internal consistency check has failed. This usually indicates an internal error in the Run-Time Library and should be reported to your HP support representative. LIB$_INSVIRMEM Insufficient virtual memory. Your program has exceeded the image quota for virtual memory. LIB$_INVSTRDES Invalid string descriptor. A string descriptor has an invalid value in its CLASS field.
The Copy Source String Passed by Reference to Destination String routine copies a source string passed by reference to a destination string, passed by descriptor.
LIB$SCOPY_R_DX_64 quad-integer-source-length ,source-string ,destination-string
OpenVMS usage: cond_value type: longword (unsigned) access: write only mechanism: by value
quad-integer-source-length
OpenVMS usage: quadword_unsigned type: quadword (unsigned) access: read only mechanism: by reference
Length of the source string in bytes. The quad-integer-source-length argument is the address of an unsigned quadword that contains the length of the source string.source-string
OpenVMS usage: char_string type: character string access: read only mechanism: by reference
Source string to be copied to the destination string by LIB$SCOPY_R_DX_64. The source-string argument is the address of this source string.destination-string
OpenVMS usage: char_string type: character string access: write only mechanism: by descriptor
Destination string to which the source string is copied. The destination-string argument contains the address of a descriptor pointing to this destination string.
LIB$SCOPY_R_DX_64 copies a source string, passed by reference, to a destination string, passed by descriptor. It returns the status as a condition value. Truncation is a qualified success; LIB$SCOPY_R_DX_64 sets bit 0 of the condition value to 1.The actions taken by LIB$SCOPY_R_DX_64 depend on the descriptor class of the destination string. The following table describes these actions for each descriptor class:
Descriptor Class Action S, Z, SD, A, NCA Copy the source string. If needed, space fill or truncate on the right. D If the area specified by the destination descriptor is large enough to contain the source string, copy the source string and set the new length in the destination descriptor. If the area specified is not large enough, return the previous space allocation, if any, and then dynamically allocate the amount of space needed. Copy the source string and set the new length and address in the destination descriptor. VS Copy source string to destination string up to the limit of the descriptor's MAXSTRLEN field with no padding. Readjust the string's current length (CURLEN) field to the actual number of bytes copied.
SS$_NORMAL Routine successfully completed. All characters in the input string were copied to the destination string. LIB$_STRTRU Routine successfully completed. String truncated. The destination string could not contain all of the characters copied from the source string. LIB$_FATERRLIB Fatal internal error. An internal consistency check has failed. This usually indicates an internal error in the Run-Time Library and should be reported to your HP support representative. LIB$_INSVIRMEM Insufficient virtual memory. Your program has exceeded the image quota for virtual memory. LIB$_INVSTRDES Invalid string descriptor. A string descriptor has an invalid value in its CLASS field.
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