Difference between revisions of "Bcopy"
m |
m |
||
| Line 1: | Line 1: | ||
The bcopy command is used to copy a (part of a) [[:Category:Binary Files|binary file]]. | The bcopy command is used to copy a (part of a) [[:Category:Binary Files|binary file]]. | ||
<nowiki>bcopy [-zc] <©> <N> <&source> <S> <M></nowiki> | <nowiki>bcopy [-zc] <©> <N> <&source> <S> <M></nowiki> | ||
| − | This copies M bytes from &source starting at position S to © starting at position N. | + | This copies ''M'' bytes from ''&source'' starting at position ''S'' to ''©'' starting at position ''N''. |
| − | If © doesn't exist yet, the binary file will be created and zero filled to the | + | If ''©'' doesn't exist yet, the binary file will be created and zero filled to the ''N''th byte. If ''©'' already exists but smaller then ''N'' bytes, it will be extended with zeros to the ''N''th byte. If ''©'' already exists and is ''N'' bytes or larger, the copied bytes will overwrite the old bytes in ''©''. |
| − | If &source is smaller then S + M - 1 bytes and &source is equal or larger then S bytes, then all bytes starting from S to the last byte will be copied. If &source is smaller then S bytes, you will get an error. | + | If ''&source'' is smaller then ''S'' + ''M'' - 1 bytes and ''&source'' is equal or larger then ''S'' bytes, then all bytes starting from ''S'' to the last byte will be copied. If ''&source'' is smaller then ''S'' bytes, you will get an error. |
| − | You can use M = -1 to copy all bytes starting from byte S to the last byte. | + | You can use ''M'' = -1 to copy all bytes starting from byte ''S'' to the last byte. |
| − | The -z switch will zero fill all bytes in &source that were copied. | + | The ''-z'' switch will zero fill all bytes in ''&source'' that were copied. |
| − | The -c switch will chop © to N + M bytes. | + | The ''-c'' switch will chop ''©'' to ''N'' + ''M'' bytes. |
== Examples == | == Examples == | ||
Revision as of 19:35, 13 October 2006
The bcopy command is used to copy a (part of a) binary file.
bcopy [-zc] <©> <N> <&source> <S> <M>
This copies M bytes from &source starting at position S to © starting at position N. If © doesn't exist yet, the binary file will be created and zero filled to the Nth byte. If © already exists but smaller then N bytes, it will be extended with zeros to the Nth byte. If © already exists and is N bytes or larger, the copied bytes will overwrite the old bytes in ©. If &source is smaller then S + M - 1 bytes and &source is equal or larger then S bytes, then all bytes starting from S to the last byte will be copied. If &source is smaller then S bytes, you will get an error. You can use M = -1 to copy all bytes starting from byte S to the last byte.
The -z switch will zero fill all bytes in &source that were copied. The -c switch will chop © to N + M bytes.
Examples
bset &data 1 65 66 67 68 69 bcopy &test 1 &data 3 2 echo -a $bvar(&test,1,$bvar(&test,0)) returns 67 68
This will copy the values 67 68 from &data to the first position of &test.
bset &data 1 65 66 67 68 69 bset &test 1 97 bcopy &test 5 &data 4 -1 echo -a $bvar(&test,1,$bvar(&test,0)) returns 97 0 0 0 68 69
This will copy values 68 69 from &data to the fifth postion of &test. Positions 2-4 of &test will be zero filled.
bset &data 1 65 66 67 68 69 bset &test 1 97 98 99 100 bcopy -z &test 2 &data 3 2 echo -a $bvar(&data,1,$bvar(&data,0)) returns 65 66 0 0 69 echo -a $bvar(&test,1,$bvar(&test,0)) returns 97 67 68 100
This will copy values 67 68 from &data to the second position of &test. The -z switch will replace the copied values 67 68 of &data to zeros. Notice that values 98 99 will be overwritten.
bset &data 1 65 66 67 68 69 bset &test 1 97 98 99 100 bcopy -c &test 2 &data 3 2 echo -a $bvar(&test,1,$bvar(&test,0)) returns 97 67 68
This will copy values 67 68 from &data to the second position of &test. The -c switch will chop value 100.
