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Last modified: Fri Feb 2 17:44:54 2001.
Project : SOHO - CDS Name : CHECK_TAPE_DRV Purpose : Associates tape drive numbers with device files. *Unix only* Explanation : This is an internal routine to the CDS/SERTS Unix tape handling utilities. It converts tape drive numbers to actual device names, and checks to make sure that the device file is open. **Unix only** Use : CHECK_TAPE_DRV, UNIT, LOGICAL_DRIVE, DRIVE, LUN Inputs : UNIT = Tape unit number. Tape drives are selected via the UNIX environment variables "MT1", "MT2", etc. The desired tape drive is thus specified by numbers, as in VMS. Must be from 0 to 9. Opt. Inputs : None. Outputs : LOGICAL_DRIVE = Name of environment variable pointing to tape drive device file, e.g. "MT0". DRIVE = Name of device file, e.g. '/dev/nrst0'. LUN = Logical unit number used for reads and writes. Opt. Outputs: None. Keywords : None. Calls : None. Common : CHCK_TAPE_DRVS contains array TAPE_LUN, containing logical unit numbers for each tape device, and TAPE_OPEN, which tells whether each device is open or not. Restrictions: The environment variable "MTn", where n corresponds to the variable UNIT, must be defined. E.g., setenv MT0 /dev/nrst0 Requires IDL v3.1 or later. Side effects: If the device file is not yet open, then the tape is rewound, and a file unit is opened to it. Category : Utilities, I/O, Tape. Prev. Hist. : William Thompson, Apr 1991. Written : William Thompson, GSFC, April 1991. Modified : Version 1, William Thompson, GSFC, 21 December 1993. Added keyword /NOSTDIO to OPEN statement. Incorporated into CDS library. Version 2, William Thompson, GSFC, 22 December 1993. Added spawn to "mt rewind". Version : Version 2, 22 December 1993.
Project : SOHO - CDS Name : DISMOUNT Purpose : Emulates the VMS DISMOUNT function in Unix. Explanation : Emulates the VMS DISMOUNT function in the Unix environment. Although this is not a standard IDL function, it is available as a separate LINKIMAGE routine for VMS. The main purpose of this procedure is to close the file unit open on the tape device, and optionally to unload the tape. Errors can result if the tape is unloaded manually rather than using this routine. **Unix only** Use : DISMOUNT, UNIT Inputs : UNIT = Tape unit number. Tape drives are selected via the UNIX environment variables "MT1", "MT2", etc. The desired tape drive is thus specified by numbers, as in VMS. Must be from 0 to 9. Opt. Inputs : None. Outputs : None. Opt. Outputs: None. Keywords : NOUNLOAD = If set, then the tape is simply rewound, not taken off line. Calls : CHECK_TAPE_DRV Common : CHCK_TAPE_DRVS contains array TAPE_LUN, containing logical unit numbers for each tape device, and TAPE_OPEN, which tells whether each device is open or not. Restrictions: The environment variable "MTn", where n corresponds to the variable UNIT, must be defined. E.g., setenv MT0 /dev/nrst0 Requires IDL v3.1 or later. Side effects: The device file is opened. Category : Utilities, I/O, Tape. Prev. Hist. : None. Written : William Thompson, GSFC, 21 December 1993. Modified : Version 1, William Thompson, GSFC, 21 December 1993. Version : Version 1, 21 December 1993.
Project : SOHO - CDS Name : REWIND Purpose : Emulates the VMS REWIND function in Unix. Explanation : Emulates the VMS REWIND function in the Unix environment. **Unix only** Use : REWIND, UNIT Inputs : UNIT = Tape unit number. Tape drives are selected via the UNIX environment variables "MT1", "MT2", etc. The desired tape drive is thus specified by numbers, as in VMS. Must be from 0 to 9. Opt. Inputs : None. Outputs : None. Opt. Outputs: None. Keywords : None. Calls : CHECK_TAPE_DRV Common : None. Restrictions: The environment variable "MTn", where n corresponds to the variable UNIT, must be defined. E.g., setenv MT0 /dev/nrst0 Requires IDL v3.1 or later. Side effects: The device file is opened. Category : Utilities, I/O, Tape. Prev. Hist. : VERSION 1, R. W. Thompson 11/30/89 William Thompson, Apr 1991, rewrote to better emulate VMS version. Written : R. W. Thompson, GSFC/IUE, 30 November 1989. Modified : Version 1, William Thompson, GSFC, 21 December 1993. Rewrote to use IOCTL. Version : Version 1, 21 December 1993.
Project : SOHO - CDS Name : SKIPF Purpose : Emulates the VMS SKIPF function on UNIX machines. Explanation : Emulates the VMS SKIPF function on UNIX machines. Use : SKIPF, UNIT, NSKIP SKIPF, UNIT, NSKIP, RECORDS Inputs : UNIT = Tape unit number. Tape drives are selected via the UNIX environment variables "MT1", "MT2", etc. The desired tape drive is thus specified by numbers, as in VMS. Must be from 0 to 9. NSKIP = Number of files or records to skip. Opt. Inputs : RECORDS = If present, then records are skipped instead of files. Outputs : None. However, !ERR is set to ABS(NSKIP) Opt. Outputs: None. Keywords : None. Calls : CHECK_TAPE_DRV Common : None. Restrictions: This routine may not act exactly the same as the VMS equivalent, particularly in regards to the behavior of the !ERR system variable. The environment variable "MTn", where n corresponds to the variable UNIT, must be defined. E.g., setenv MT0 /dev/nrst0 Requires IDL v3.1 or later. Side effects: The device file is opened. !ERR is set to ABS(NSKIP). Category : Utilities, I/O, Tape. Prev. Hist. : VERSION 1, R. W. Thompson 12/4/89 William Thompson, Apr 1991, rewrote to better emulate VMS version. Written : R. W. Thompson, GSFC/IUE, 4 December 1989. Modified : Version 1, William Thompson, GSFC, 21 December 1993. Rewrote to use IOCTL. Version : Version 1, 21 December 1993.
Project : SOHO - CDS Name : TAPRD Purpose : Emulates VMS TAPRD procedure on UNIX machines. Explanation : Emulates VMS TAPRD procedure on UNIX machines. However, the actions of this routine may differ from the VMS equivalent in nonstandard situations. *** Unix only *** Use : TAPRD, ARRAY, UNIT [, BYTE_REVERSE ] Inputs : ARRAY = Variable into which the data should be read. The datatype and number of values to attempt to read is based on this array. UNIT = Specifies the magnetic tape unit. Not to be confused with logical unit numbers. In UNIX, the number refers to one of the environment variables MT0, MT1, etc., which translate into a physical device name, e.g. setenv MT0 /dev/nrst0 Opt. Inputs : BYTE_REVERSE = If present, then even and odd bytes are swapped. Outputs : The output is read into ARRAY. Also, !ERR is set to the number of bytes actually read. Opt. Outputs: None. Keywords : None. Calls : CHECK_TAPE_DRV Common : None. Restrictions: This routine may not have all the abilities of the VMS equivalent, particularly in regards to the !ERR system variable. The environment variable "MTn", where n corresponds to the variable UNIT, must be defined. E.g., setenv MT0 /dev/nrst0 Requires IDL v3.1 or later. Side effects: The device file is opened. Category : Utilities, I/O, Tape. Prev. Hist. : William Thompson, GSFC, June 1991. Written : William Thompson, GSFC, June 1991. Modified : Version 1, William Thompson, GSFC, 21 December 1993. Rewrote to use READU with TRANSFER_COUNT keyword. Version 2, William Thompson, GSFC, 22 December 1993. Added check of ARRAY variable. Version : Version 2, 22 December 1993.
Project : SOHO - CDS Name : TAPWRT Purpose : Emulates VMS TAPWRT procedure on UNIX machines. Explanation : Emulates VMS TAPWRT procedure on UNIX machines. *** Unix only *** Use : TAPWRT, ARRAY, UNIT [, BYTE_REVERSE ] Inputs : ARRAY = Variable into which the data should be read. UNIT = Specifies the magnetic tape unit. Not to be confused with logical unit numbers. In UNIX, the number refers to one of the environment variables MT0, MT1, etc., which translate into a physical device name, e.g. setenv MT0 /dev/nrst0 Opt. Inputs : BYTE_REVERSE = If present, then even and odd bytes are swapped. Outputs : None. Opt. Outputs: None. Keywords : None. Calls : CHECK_TAPE_DRV Common : None. Restrictions: The environment variable "MTn", where n corresponds to the variable UNIT, must be defined. E.g., setenv MT0 /dev/nrst0 Requires IDL v3.1 or later. Side effects: The device file is opened. Category : Utilities, I/O, Tape. Prev. Hist. : William Thompson, GSFC, June 1991. Written : William Thompson, GSFC, June 1991. Modified : Version 1, William Thompson, GSFC, 21 December 1993. Rewrote to use WRITEU. Version : Version 1, 21 December 1993.
Project : SOHO - CDS Name : WEOF Purpose : Emulates the VMS WEOF routine on UNIX machines. Explanation : Emulates the VMS WEOF routine on UNIX machines. *** Unix only *** Use : WEOF, UNIT Inputs : UNIT = Tape unit number. Tape drives are selected via the UNIX environment variables "MT1", "MT2", etc. The desired tape drive is thus specified by numbers, as in VMS. Must be from 0 to 9. Opt. Inputs : None. Outputs : None. Opt. Outputs: None. Keywords : None. Calls : CHECK_TAPE_DRV Common : None. Restrictions: The environment variable "MTn", where n corresponds to the variable UNIT, must be defined. E.g., setenv MT0 /dev/nrst0 Requires IDL v3.1 or later. Side effects: The device file is opened. Category : Utilities, I/O, Tape. Prev. Hist. : VERSION 1, R. W. Thompson 11/30/89 William Thompson, Apr 1991, rewrote to better emulate VMS version. Written : R. W. Thompson, GSFC/IUE, 30 November 1989. Modified : Version 1, William Thompson, GSFC, 21 December 1993. Rewrote to use IOCTL. Version : Version 1, 21 December 1993.