(standards.info) Syntactic Conventions

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 Clean Use of C Constructs
 =========================
 
    Please explicitly declare all arguments to functions.  Don't omit
 them just because they are `int's.
 
    Declarations of external functions and functions to appear later in
 the source file should all go in one place near the beginning of the
 file (somewhere before the first function definition in the file), or
 else should go in a header file.  Don't put `extern' declarations inside
 functions.
 
    It used to be common practice to use the same local variables (with
 names like `tem') over and over for different values within one
 function.  Instead of doing this, it is better declare a separate local
 variable for each distinct purpose, and give it a name which is
 meaningful.  This not only makes programs easier to understand, it also
 facilitates optimization by good compilers.  You can also move the
 declaration of each local variable into the smallest scope that includes
 all its uses.  This makes the program even cleaner.
 
    Don't use local variables or parameters that shadow global
 identifiers.
 
    Don't declare multiple variables in one declaration that spans lines.
 Start a new declaration on each line, instead.  For example, instead of
 this:
 
      int    foo,
             bar;
 
 write either this:
 
      int foo, bar;
 
 or this:
 
      int foo;
      int bar;
 
 (If they are global variables, each should have a comment preceding it
 anyway.)
 
    When you have an `if'-`else' statement nested in another `if'
 statement, always put braces around the `if'-`else'.  Thus, never write
 like this:
 
      if (foo)
        if (bar)
          win ();
        else
          lose ();
 
 always like this:
 
      if (foo)
        {
          if (bar)
            win ();
          else
            lose ();
        }
 
    If you have an `if' statement nested inside of an `else' statement,
 either write `else if' on one line, like this,
 
      if (foo)
        ...
      else if (bar)
        ...
 
 with its `then'-part indented like the preceding `then'-part, or write
 the nested `if' within braces like this:
 
      if (foo)
        ...
      else
        {
          if (bar)
            ...
        }
 
    Don't declare both a structure tag and variables or typedefs in the
 same declaration.  Instead, declare the structure tag separately and
 then use it to declare the variables or typedefs.
 
    Try to avoid assignments inside `if'-conditions.  For example, don't
 write this:
 
      if ((foo = (char *) malloc (sizeof *foo)) == 0)
        fatal ("virtual memory exhausted");
 
 instead, write this:
 
      foo = (char *) malloc (sizeof *foo);
      if (foo == 0)
        fatal ("virtual memory exhausted");
 
    Don't make the program ugly to placate `lint'.  Please don't insert
 any casts to `void'.  Zero without a cast is perfectly fine as a null
 pointer constant, except when calling a varargs function.
 

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