Difference between revisions of "Bset"
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The bset command is used to set a [[:Category:Binary Files|binary file]]. | 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 ''N''th byte of the binary file &binvar to the [[$asc|asciivalues]]. All asciivalues after are set to positions after the | + | This sets the ''N''th byte of the binary file ''&binvar'' to the [[$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 ''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. | 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. | ||
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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 | ||
− | echo -a $bvar(&test,1,$bvar(&test,0)) ''106 117 115 116 32 97 32 116 101 115 116'' | + | 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" | 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" | ||
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"