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| author | Tobias Klauser <tklauser@distanz.ch> | 2008-01-27 11:37:44 +0100 |
|---|---|---|
| committer | Tobias Klauser <tklauser@xenon.tklauser.home> | 2008-01-27 11:37:44 +0100 |
| commit | 7e0f021a9aec35fd8e6725e87e3313b101d26f5e (patch) | |
| tree | b1cacc4b24393f517aeb4610e9e1021f954307a8 /reference/C/SYNTAX/preprocessors.html | |
Initial import (2.0.2-6)2.0.2-6
Diffstat (limited to 'reference/C/SYNTAX/preprocessors.html')
| -rw-r--r-- | reference/C/SYNTAX/preprocessors.html | 83 |
1 files changed, 83 insertions, 0 deletions
diff --git a/reference/C/SYNTAX/preprocessors.html b/reference/C/SYNTAX/preprocessors.html new file mode 100644 index 0000000..5885253 --- /dev/null +++ b/reference/C/SYNTAX/preprocessors.html @@ -0,0 +1,83 @@ +<title>C compiler preprocessors</title> +<head> +<script language="JavaScript"> +</script> +</head> +<body bgcolor="#ffffcc"> +<hr> +<center> +<h1>C compiler preprocessors</h1> +</center> +<hr> + +Preprocessor commands are executed before the compiler compiles the +source code. These commands will change the original code usually to +suit the operating environment and/or to add code that will be required by +calls to library functions. Preprocessors are recognised by the leading +# in their names. +<p> +<table border=2 bgcolor=ivory> +<Caption>Preprocessors</caption> +<tr> +<td><a href="include_preprocessor.html">#include</a> <td>Insert a source file. +<tr> +<td><a href="define_preprocessor.html">#define</a> <td>Define a preprocessor +constant. +<tr> +<td><a href="../EXAMPLES/if_else_endif.c">#if</a> <td>Branch based on an expression. +<tr> +<td>#ifdef <td>Branch if preprocessor constant has been defined? +<tr> +<td><a href="../EXAMPLES/ifndef.c">#ifndef</a> <td> Branch is a preprocessor +constant has NOT been defined. +<tr> +<td>#line <td> Specify the number of the next source line. +<tr> +<td>#undef <td> Remove a preprocessor constant. +<tr> +<td>#pragma<td> Perform an implementation dependent action??? +<tr> +<td><a href="../EXAMPLES/if_else_endif.c">#else</a> <td> Executed if #if +#ifdef or #ifndef fails. +<tr> +<td>#error <td> Write an error message. +<tr> +<td>#elif <td> Executed when an #if fails. +<tr> +<td><a href="../EXAMPLES/if_else_endif.c">#endif</a> <td>Close #if #ifdef or +#ifndef +</table> +<hr> +<H2>Notes:</H2> +<ul> +<li>Preprocessors should start in column 1. +<li>The -E option tells gcc to stop after the preprocessor stage and send the +O/P to STDOUT (usually the screen). +</ul> + + +<p> + +<hr> +<p> +<center> +<table border=2 width="80%" bgcolor="ivory"> +<tr align=center> +<td width="25%"> +<a href="../cref.html"> Top</a> +</td><td width="25%"> +<a href="../master_index.html"> Master Index</a> +</td><td width="25%"> +<a href="keywords.html"> Keywords</a> +</td><td width="25%"> +<a href="../FUNCTIONS/funcref.htm"> Functions</a> +</td> +</tr> +</table> +</center> +<p> +<hr> +<address>Martin Leslie +</address><p> +</body> +</html> |