Fwrite: Difference between revisions
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''' | == Notes == | ||
* The file handler must be [[Fopen|opened]] before using /fwrite. | |||
* When the file handler is first opened the pointer is at the end of the file so any /fwrite's upon opening the file handler will be appended to the file. | |||
* When writing to the file handler you're never inserting data, you're overwriting data unless the data you're writing at the pointer exceeds the end of the file. | |||
If you have a file containing this data below opened in a file handler called ''test'': | |||
A duck goes quack | |||
Dogs go woof | |||
Fish go moo | |||
Dana is silent but deadly | |||
And you issue the command: | |||
/[[fseek]] test -l 1 | |||
/fwrite -n test Ducks go quack | |||
You will end up with a file containing: | |||
Ducks go quack | |||
k | |||
Dogs go woof | |||
Fish go moo | |||
Dana is silent but deadly | |||
The reason for this is /fwrite overwrites the same amount of data (unless exceeding the end of the file) from the file handler that you're writing (plus two if you issue -n for the [[$crlf]]) | |||
A duck goes qu ac k[[$crlf|<crlf>]] | |||
Ducks go quack [[$crlf|<crlf>]] | |||
The data, ''A duck goes qu'' is overwritten with ''Ducks go quack'' the original ''ac'' is overwritten with the [[$crlf|<crlf>]] from the -n switch leaving the k[[$crlf|<crlf>]] that was already there previously. | |||
== Example == | == Example == |
Latest revision as of 07:51, 26 January 2009
Writes text or the specified binary variable to the file.
/fwrite [-bn] <name> <text | &binvar>
Explanation of the switches:
Switch | Meaning |
b | indicates that a &binvar is being specified |
n | appends a $crlf to the line being written. |
Notes
- The file handler must be opened before using /fwrite.
- When the file handler is first opened the pointer is at the end of the file so any /fwrite's upon opening the file handler will be appended to the file.
- When writing to the file handler you're never inserting data, you're overwriting data unless the data you're writing at the pointer exceeds the end of the file.
If you have a file containing this data below opened in a file handler called test:
A duck goes quack Dogs go woof Fish go moo Dana is silent but deadly
And you issue the command:
/fseek test -l 1 /fwrite -n test Ducks go quack
You will end up with a file containing:
Ducks go quack k Dogs go woof Fish go moo Dana is silent but deadly
The reason for this is /fwrite overwrites the same amount of data (unless exceeding the end of the file) from the file handler that you're writing (plus two if you issue -n for the $crlf)
A duck goes qu ac k<crlf> Ducks go quack <crlf>
The data, A duck goes qu is overwritten with Ducks go quack the original ac is overwritten with the <crlf> from the -n switch leaving the k<crlf> that was already there previously.
Example
/fwrite moo moo!
This will just add moo! to the end of the file assigned to the name moo.
/fwrite -n moo moo!
This will add moo! and a $crlf to the end of the file assigned to the name moo.
/fwrite -b moo &moo
This will add the content of the Binary Variable &moo to the end of the file assigned to the name moo.