This macro, `%mp_binarycopy`, allows duplicating a file by reading it byte by byte and rewriting it. It supports specifying existing file paths ('inloc', 'outloc') or filerefs ('inref', 'outref'). It can either create a new file or append content to an existing file via the 'mode=APPEND' option. The macro manages the creation and release of temporary filerefs if file paths are provided. It is designed to be a robust and operating system agnostic copy method. An important note mentions that for more recent SAS© versions and if features like appending are not necessary, the `fcopy()` function could be a simpler alternative.
Data Analysis
Type : EXTERNAL
The macro operates on external files whose paths or filerefs are provided as parameters (`inloc`, `outloc`, `inref`, `outref`). It does not generate internal data for its own processing but manipulates existing or to-be-created binary files.
1 Code Block
MACRO DEFINITION
Explanation :
Definition of the `%mp_binarycopy` macro with its input parameters, including file paths (inloc, outloc), file references (inref, outref), operation mode (CREATE or APPEND) and an execution condition (iftrue). The macro includes a local variable 'mod' and an early exit condition.
Definition of the `%mp_binarycopy` macro with its input parameters, including file paths (inloc, outloc), file references (inref, outref), operation mode (CREATE or APPEND) and an execution condition (iftrue). The macro includes a local variable 'mod' and an early exit condition.
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| 1 | %macro mp_binarycopy( |
| 2 | inloc= /* full path and filename of the object to be copied */ |
| 3 | ,outloc= /* full path and filename of object to be created */ |
| 4 | ,inref=____in /* override default to use own filerefs */ |
| 5 | ,outref=____out /* override default to use own filerefs */ |
| 6 | ,mode=CREATE |
| 7 | ,iftrue=%str(1=1) |
| 8 | )/*/STORE SOURCE*/; |
| 9 | %local mod; |
| 10 | |
| 11 | %IF not(%eval(%unquote(&iftrue))) %THEN %return; |
2 Code Block
Pre-processing (Filerefs)
Explanation :
This section configures the input and output filerefs. If the `inref` or `outref` parameters have not been overridden, the macro creates temporary filerefs (`____in`, `____out`) pointing to the paths specified by `inloc` and `outloc`. The `lrecl=1048576` option defines the logical record length, and `&mod` is added to the output fileref if the mode is 'APPEND'.
This section configures the input and output filerefs. If the `inref` or `outref` parameters have not been overridden, the macro creates temporary filerefs (`____in`, `____out`) pointing to the paths specified by `inloc` and `outloc`. The `lrecl=1048576` option defines the logical record length, and `&mod` is added to the output fileref if the mode is 'APPEND'.
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| 1 | %IF &mode=APPEND %THEN %let mod=mod; |
| 2 | |
| 3 | /* these IN and OUT filerefs can point to anything */ |
| 4 | %IF &inref = ____in %THEN %DO; |
| 5 | filename &inref &inloc lrecl=1048576 ; |
| 6 | %END; |
| 7 | %IF &outref=____out %THEN %DO; |
| 8 | filename &outref &outloc lrecl=1048576 &mod; |
| 9 | %END; |
3 Code Block
DATA STEP
Explanation :
Central block of the macro, using a `DATA _null_` step. It reads the input file (`infile`) byte by byte (`lrecl=1 recfm=n`) and writes each byte directly to the output file (`file`). `sourcechar $char1.` reads a character, `format sourcechar hex2.` formats it as hexadecimal, and `put sourcechar char1.` writes it as a single character, ensuring a binary copy.
Central block of the macro, using a `DATA _null_` step. It reads the input file (`infile`) byte by byte (`lrecl=1 recfm=n`) and writes each byte directly to the output file (`file`). `sourcechar $char1.` reads a character, `format sourcechar hex2.` formats it as hexadecimal, and `put sourcechar char1.` writes it as a single character, ensuring a binary copy.
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| 1 | /* copy the file byte-for-byte */ |
| 2 | DATA _null_; |
| 3 | INFILE &inref lrecl=1 recfm=n; |
| 4 | file &outref &mod recfm=n; |
| 5 | INPUT sourcechar $char1. @code_sas_json/hsdua2304@gmail.com_SAS_Assignment_2.json; |
| 6 | FORMAT sourcechar hex2.; |
| 7 | put sourcechar char1. @code_sas_json/hsdua2304@gmail.com_SAS_Assignment_2.json; |
| 8 | RUN; |
4 Code Block
Post-processing (Filerefs Release)
Explanation :
After the copy operation, this section ensures that temporary filerefs (`____in`, `____out`) created by the macro are released (`filename ... clear;`), thus avoiding naming conflicts and unnecessary resource consumption.
After the copy operation, this section ensures that temporary filerefs (`____in`, `____out`) created by the macro are released (`filename ... clear;`), thus avoiding naming conflicts and unnecessary resource consumption.
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| 1 | %IF &inref = ____in %THEN %DO; |
| 2 | filename &inref clear; |
| 3 | %END; |
| 4 | %IF &outref=____out %THEN %DO; |
| 5 | filename &outref clear; |
| 6 | %END; |
| 7 | %mend mp_binarycopy; |
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Copyright Info : Copyright (c) 2001-2006 Rodney Sparapani
