LINT(1)                              BSD                               LINT(1)



NAME
     lint - a C program verifier

SYNOPSIS
     lint [ -abchnpuvx ] file ...

DESCRIPTION
     lint attempts to detect features of C program files that are likely to be
     erroneous, non-portable, or wasteful.  It also checks the type usage of
     the program more strictly than the compilers, searching for unreachable
     statements, loops not entered at the top, automatic variables declared
     and not used, and logical expressions whose value is constant.  Moreover,
     lint looks for functions that return values in some places and not in
     others, functions that are called with varying numbers of arguments, and
     functions whose values are not used.

     By default, lint assumes that all the files are to be loaded together.
     It checks them for mutual compatibility.  Function definitions for
     certain libraries are available to lint.  These libraries are referenced
     by a conventional name, such as -lm, in the style of ld(1).  Arguments
     ending in .ln are also treated as library files.

OPTIONS
     You can use any number of the options listed below.  lint also recognizes
     the -D, -U, and -I options of cc(1) as separate arguments.

     -p        Attempt to check portability to the IBM and GCOS dialects of C.

     -h        Apply a number of heuristic tests to attempt to intuit bugs,
               improve style, and reduce waste.

     -b        Report break statements that cannot be reached.  This is not
               the default, because most lex(1) and many yacc(1) outputs
               produce dozens of such comments.

     -v        Suppress complaints about unused arguments in functions.

     -x        Report variables referred to by external declarations, but
               never used.

     -a        Report assignments of long values to integer variables.

     -c        Complain about casts that have questionable portability.

     -u        Do not complain about functions and variables used and not
               defined, or defined and not used.  This is suitable for running
               lint on a subset of files from a larger program.

     -n        Do not check compatibility against the standard library.

     -z        Do not complain about structures that are never defined (for
               example, allow the use of a structure pointer without knowing
               its contents).

     -C        Create lint libraries, as in lint -Cfoo files . . .  where
               files are the C sources of library foo.  The result is a file
               llib-lfoo.ln in the correct library format suitable for linting
               programs using foo.

C SOURCE COMMENTS
     Certain conventional comments in the C source change the behavior of

     lint:

     /*NOTREACHED*/
          At appropriate points, stops comments about unreachable code.

     /*VARARGSn*/
          Suppresses the usual checking for variable numbers of arguments in
          the following function declaration.  Checks the data types of the
          first n arguments.  Takes a missing n to be 0.

     /*NOSTRICT*/
          Shuts off strict type checking in the next expression.

     /*ARGSUSED*/
          Turns on the -v option for the next function.

     /*LINTLIBRARY*/
          At the beginning of a file, shuts off complaints about unused
          functions in the file.

FILES
     /usr/lib/lint/lint[12]      Programs
     /usr/lib/lint/llib-lc.ln    Declarations for standard functions
     /usr/lib/lint/llib-lc       Human-readable version of the above declarations file
     /usr/lib/lint/llib-port.ln  Declarations for portable functions
     /usr/lib/lint/llib-port     Human readable . . .
     llib-l*.ln                  Library created with -C

BUGS
     lint does not understand functions that do not return, for example,
     exit(2).

     There are some things you just can't get lint to shut up about.

     /*NOSTRICT*/ is not implemented in the current version.

SEE ALSO
     cc(1), ld(1)