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webbone
Joined: 20 Sep 2004
Posts: 14
Location: Sacramento, CA
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| printf to a function - possible to return error? |
 Posted: Sun Mar 20, 2005 3:49 pm |
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I know you can use printf to send output a character at a time to a function:
| Code: | | printf(MyFunction,"%03LX",myvar); |
If MyFunction() in the above example can return an error value (0=success, 1=failure, etc.) is there any way to either
A) 'break out of' the printf() on the first error
B) return the error code from the printf() rather than having to use a global variable
The function in question will be accessing hardware which may or may not respond; in the case of non-response there is a timeout in the function. It would be nice to not keep trying further characters from the printf() if the hardware is not responding.
If nothing else I can sprintf() and pass a pointer to the resulting string, but I figured I would ask in case a more elegant solution is possible. |
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Ttelmah
Guest
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| Posted: Mon Mar 21, 2005 5:16 am |
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There are some 'kludge' ways you could do this. If (for instance), you declare a global 'timeout' variable, and have the routine, set this when a timeout occurs, but also stop actually printing the characters, when it is set, then the code can check for this, and retry. So something like:
| Code: |
int1 timeout=false;
void output_char(int8 c) {
if (timeout) return;
//Here try to print the character
//Set 'timeout' if there is a problem
if (fault) timeout=true;
}
while {
printf(output_char,"Whatever you want");
if (!timeout) break;
//Here have an error 'handler' if timeout is set
timeout=false;
//I show the code as retrying to send, if a timeout has occurred
}
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Best Wishes |
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