Difference between revisions of "Bset"

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The bset command is used to set a [[Binary Files|binary file]].
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The bset command is used to set a [[:Category:Binary Files|binary file]].
 
  <nowiki>bset [-t] <&binvar> <N> <asciivalue> [asciivalue ... asciivalue]</nowiki>
 
  <nowiki>bset [-t] <&binvar> <N> <asciivalue> [asciivalue ... asciivalue]</nowiki>
This sets the Nth byte of the binary file &binvar to the asciivalues. All asciivalues after are set to positions after the Nth byte.
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This sets the ''N''th byte of the binary file ''&binvar'' to the [[$asc|asciivalues]]. All asciivalues after are set to positions after the ''N''th byte.
If you set a binary file that doesn't exist yet, the file will be created and zero filled to the Nth byte. If you set a binary file that already exists and is smaller then N bytes, it will be extended with zeros to the Nth byte.
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If you set a binary file that doesn't exist yet, the file will be created and zero filled to the ''N''th byte. If you set a binary file that already exists and is smaller then ''N'' bytes, it will be extended with zeros to the ''N''th byte.
  
The -t switch indicates that bset should treat the values as plain text and copy them directly into the binary file.
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The ''-t'' switch indicates that bset should treat the values as plain text and copy them directly into the binary file.
  
 
== Examples ==
 
== Examples ==
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Now &test is filled with 1 byte, and it containes asciivalue 65 wich is "A".
 
Now &test is filled with 1 byte, and it containes asciivalue 65 wich is "A".
 
  bset &test 5 65
 
  bset &test 5 65
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[[echo]] -a [[$bvar]](&test,1,$bvar(&test,0)) returns ''0 0 0 0 65'' 
 
In this case we only set one asciivalue at the 5th place, but the first 4 bytes are filled with zeros.
 
In this case we only set one asciivalue at the 5th place, but the first 4 bytes are filled with zeros.
 
  bset &test 1 65
 
  bset &test 1 65
 
  bset &test 5 66
 
  bset &test 5 66
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echo -a $bvar(&test,1,5) returns ''65 0 0 0 66''
 
Now we first set 65 at byte one, then set 66 at byte 5. With this second set, bytes 2 to 4 were filled with zeros.
 
Now we first set 65 at byte one, then set 66 at byte 5. With this second set, bytes 2 to 4 were filled with zeros.
 
  bset -t &test 1 just a test
 
  bset -t &test 1 just a test
Using the -t switch the text will be converted to asciivalues and set to the binary file.
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echo -a $bvar(&test,1,$bvar(&test,0)) returns ''106 117 115 116 32 97 32 116 101 115 116''
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Using the -t switch the text will be converted to asciivalues and set to the binary file. The echo returns the asciivalues of the text "just a test"
  
  
 
[[Category:Binary Files]]
 
[[Category:Binary Files]]
 
[[Category:Commands]]
 
[[Category:Commands]]

Latest revision as of 19:41, 13 October 2006

The bset command is used to set a binary file.

bset [-t] <&binvar> <N> <asciivalue> [asciivalue ... asciivalue]

This sets the Nth byte of the binary file &binvar to the asciivalues. All asciivalues after are set to positions after the Nth byte. If you set a binary file that doesn't exist yet, the file will be created and zero filled to the Nth byte. If you set a binary file that already exists and is smaller then N bytes, it will be extended with zeros to the Nth byte.

The -t switch indicates that bset should treat the values as plain text and copy them directly into the binary file.

Examples

bset &test 1 65

Now &test is filled with 1 byte, and it containes asciivalue 65 wich is "A".

bset &test 5 65
echo -a $bvar(&test,1,$bvar(&test,0)) returns 0 0 0 0 65  

In this case we only set one asciivalue at the 5th place, but the first 4 bytes are filled with zeros.

bset &test 1 65
bset &test 5 66
echo -a $bvar(&test,1,5) returns 65 0 0 0 66

Now we first set 65 at byte one, then set 66 at byte 5. With this second set, bytes 2 to 4 were filled with zeros.

bset -t &test 1 just a test
echo -a $bvar(&test,1,$bvar(&test,0)) returns 106 117 115 116 32 97 32 116 101 115 116

Using the -t switch the text will be converted to asciivalues and set to the binary file. The echo returns the asciivalues of the text "just a test"