Mail Archives: djgpp/1998/08/06/23:01:45
From: | "Chia" <chia AT top DOT net>
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Newsgroups: | comp.os.msdos.djgpp
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Subject: | Strange Function Behavior
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Date: | Thu, 6 Aug 1998 21:54:20 -0500
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Organization: | 404 Software
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Lines: | 66
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Message-ID: | <6qdq5j$as2@nnrp2.farm.idt.net>
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NNTP-Posting-Host: | flex-17.top.net
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To: | djgpp AT delorie DOT com
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DJ-Gateway: | from newsgroup comp.os.msdos.djgpp
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I ran into a problem with a GUI I'm writing, and after some creative problem
hunting have managed to eliminate the problem. However, I'm not sure why
what I did fixed it.
I had buttons which had text with the & symbol so that they would
underline. (e.g. "E&xit", etc.)
Anyway, I had a function that I used to parse the character array,
delete the & symbol, and return the position that it was in the string.
This function was called parseTitle().
The original function looked like this:
int parseTitle( char *name )
{
for( int i = 0; i < (int)strlen(name); i++)
{
if (name[i] == '&')
{
for( int c = i; c < (int)strlen(name); c++)
name[c] = name[c + 1];
return i;
}
}
return -1; // returns negative if not found.
}
Anyway, I had created a buttons with the text "&Show Barquie" and "&Hide
Barquie". This apparently worked fine.
Then I started work on the menus, and "&File" worked. I was making the
menu options. These options, too, used the & symbol for the underlining. I
needed some way to test my menu, and I used "&Show Barquie" and "&Hide
Barquie".
This didn't work at all. I began to suspect the compiler was being
screwy and I posted a message about how when I passed these strings it lost
the & sign.
Well, I commented out code and found that in parseTitle, I found that
the loop
for(int c = i; c < (int)strlen(name);c++) name[c] = name[c + 1];
was causing the problems.
I rewrote the function to use strcpy() and use a temporary string, then
copy the string over, and it worked ok.
Does anyone know what was happening in the original code? I don't
understand why it would act that way. I figure it was probably something
with the name[c + 1] running over the boundaries or something, but I don't
have any idea why this would do that.
I mean, the problem was like this:
fn("&Show Barquie");
void fn(char *txt) { cout << txt; }
prints "Show Barquie". ???
Any hypotheses are welcome.
// chia AT top DOT net -- http://www.top.net/chia/
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