m4(1)								   User Commands							     m4(1)

NAME

       m4 - macro processor

SYNOPSIS

       /usr/ccs/bin/m4 [-e] [-s] [-B int] [-H int] [-S int] [-T int] [ -Dname [=val]] ... [-U name] ... [file...]

       /usr/xpg4/bin/m4 [-e] [-s] [-B int] [-H int] [-S int] [-T int] [ -Dname [ ...=val]] [-U name] ... [file...]

DESCRIPTION

       The  m4 utility is a macro processor intended as a front end for C, assembler, and other languages. Each of the argument files is processed
       in order. If there are no files, or if a file is -, the standard input is read. The processed text is written on the standard output. Note:
       m4 cannot include more than nine nested files and will write a diagnostic message if that number is exceeded.

   Macro Syntax
       Macro calls have the form:

       name(arg1,arg2, ..., argn)

       The open parenthesis character, (, must immediately follow the name of the macro. If the name of a defined macro is not followed by a (, it
       is deemed to be a call of that macro with no arguments. Potential macro names consist of alphanumeric characters and underscore (_),  where
       the first character is not a digit.

       Leading	unquoted  blanks,   <TAB>s,  and  NEWLINEs  are ignored while collecting arguments. Left and right single quotes are used to quote
       strings. The value of a quoted string is the string stripped of the quotes.

   Macro Processing
       When a macro name is recognized, its arguments are collected by searching for a matching right parenthesis. If fewer arguments are supplied
       than  are in the macro definition, the trailing arguments are taken to be NULL. Macro evaluation proceeds normally during the collection of
       the arguments, and any commas or right parentheses that happen to turn up within the value of a nested call are as effective  as  those	in
       the original input text. After argument collection, the value of the macro is pushed back onto the input stream and rescanned.

OPTIONS

       The options and their effects are as follows:

       -Bint	Changes the size of the push-back and argument collection buffers from the default of  4,096.

       -e	Operates interactively. Interrupts are ignored and the output is unbuffered.

       -Hint	Changes the size of the symbol table hash array from the default of  199. The size should be prime.

       -s	Enables line sync output for the C preprocessor (#line ...)

       -Sint	Changes the size of the call stack from the default of	100slots. Macros take three slots, and non-macro arguments take one.

       -Tint	Changes the size of the token buffer from the default of  512bytes.

       To be effective, the above flags must appear before any file names and before any -D or -U flags:

       -D name[=val]   Defines name to val or to NULL in val's absence.

       -Uname	       Undefines name.

OPERANDS

       The following operand is supported:

       file	A path name of a text file to be processed. If no file is given, or if it is -, the standard input is read.

USAGE

       The  m4 utility makes available the following built-in macros. These macros may be redefined, but once this is done the original meaning is
       lost. Their values are  NULL unless otherwise stated.

       changequote     Change quote symbols to the first and second arguments. The symbols may be up to five characters long. changequote  without
		       arguments restores the original values (that is, `').

       changecom       Change  left  and  right comment markers from the default # and NEWLINE. With no arguments, the comment mechanism is effec-
		       tively disabled. With one argument, the left marker becomes the argument and the right marker  becomes  NEWLINE.  With  two
		       arguments, both markers are affected. Comment markers may be up to five characters long.

       decr	       Returns the value of its argument decremented by 1.

       define	       The  second  argument is installed as the value of the macro whose name is the first argument. Each occurrence of $n in the
		       replacement text, where n is a digit, is replaced by the n-th argument. Argument 0 is the name of the macro; missing  argu-
		       ments are replaced by the null string; $# is replaced by the number of arguments; $* is replaced by a list of all the argu-
		       ments separated by commas; $@ is like $*, but each argument is quoted (with the current quotes).

       defn	       Returns the quoted definition of its argument(s). It is useful for renaming macros, especially built-ins.

       divert	       m4 maintains 10 output streams, numbered 0-9. The final output is the concatenation of the streams in numerical order. Ini-
		       tially  stream  0 is the current stream. The divert macro changes the current output stream to its (digit-string) argument.
		       Output diverted to a stream other than 0 through 9 is discarded.

       divnum	       Returns the value of the current output stream.

       dnl	       Reads and discards characters up to and including the next NEWLINE.

       dumpdef	       Prints current names and definitions, for the named items, or for all if no arguments are given.

       errprint        Prints its argument on the diagnostic output file.

   /usr/ccs/bin/m4
       eval	       Evaluates its argument as an arithmetic expression, using 32-bit signed-integer arithmetic.  The  following  operators  are
		       supported:  parentheses, unary -, unary +, !, ~, *, /, %, +, -, relationals, bitwise &, |, &&, and ||.	Octal and hex num-
		       bers may be specified as in C. The second argument specifies the radix for the result; the default is 10. The  third  argu-
		       ment may be used to specify the minimum number of digits in the result.

   /usr/xpg4/bin/m4
       eval	       Evaluates  its  argument  as  an arithmetic expression, using 32-bit signed-integer arithmetic. The following operators are
		       supported: parentheses, unary -, unary +, !, ~, *, /, %, +, -, <<, >>, relationals, bitwise &, |, &&, and  ||.	Precedence
		       and associativity are as in C. Octal and hex numbers may also be specified as in C. The second argument specifies the radix
		       for the result; the default is 10. The third argument may be used to specify the minimum number of digits in the result.

       ifdef	       If the first argument is defined, the value is the second argument, otherwise the third.  If there is  no  third  argument,
		       the value is  NULL. The word unix is predefined.

       ifelse	       This macro has three or more arguments. If the first argument is the same string as the second, then the value is the third
		       argument. If not, and if there are more than four arguments, the process is repeated with arguments 4, 5, 6 and	7.  Other-
		       wise, the value is either the fourth string, or, if it is not present, NULL.

       include	       Returns the contents of the file named in the argument.

       incr	       Returns	the  value  of	its  argument incremented by 1. The value of the argument is calculated by interpreting an initial
		       digit-string as a decimal number.

       index	       Returns the position in its first argument where the second argument begins (zero origin), or -1  if  the  second  argument
		       does not occur.

       len	       Returns the number of characters in its argument.

       m4exit	       This macro causes immediate exit from m4. Argument 1, if given, is the exit code; the default is  0.

       m4wrap	       Argument 1 will be pushed back at final EOF. Example: m4wrap(`cleanup()')

       maketemp        Fills in a string of "X" characters in its argument with the current process ID.

       popdef	       Removes current definition of its argument(s), exposing the previous one, if any.

       pushdef	       Like define, but saves any previous definition.

       shift	       Returns all but its first argument. The other arguments are quoted and pushed back with commas in between. The quoting nul-
		       lifies the effect of the extra scan that will subsequently be performed.

       sinclude        This macro is identical to include, except that it says nothing if the file is inaccessible.

       substr	       Returns a substring of its first argument. The second argument is a zero origin number selecting the first  character;  the
		       third argument indicates the length of the substring. A missing third argument is taken to be large enough to extend to the
		       end of the first string.

       syscmd	       This macro executes the command given in the first argument. No value is returned.

       sysval	       This macro is the return code from the last call to syscmd.

       translit        Transliterates the characters in its first argument from the set given by the second argument  to  the  set  given  by  the
		       third. No abbreviations are permitted.

       traceon	       This  macro with no arguments, turns on tracing for all macros (including built-ins). Otherwise, turns on tracing for named
		       macros.

       traceoff        Turns off trace globally and for any macros specified.

       undefine        Removes the definition of the macro named in its argument.

       undivert        This macro causes immediate output of text from diversions named as arguments, or all diversions if no argument.  Text  may
		       be undiverted into another diversion. Undiverting discards the diverted text.

EXAMPLES

       Example 1: Examples of m4 files

       If the file m4src contains the lines:

	       The value of `VER' is "VER".
	       ifdef(`VER', ``VER'' is defined to be VER., VER is not defined.)
	       ifelse(VER, 1, ``VER'' is `VER'.)
	       ifelse(VER, 2, ``VER'' is `VER'., ``VER'' is not 2.)
	       end

       then the command:

	       m4 m4src

       or the command:

	       m4 -U VER m4src

       produces the output:

	       The value of VER is "VER".
	       VER is not defined.

	       VER is not 2.
	       end

       The command:

	       m4 -D VER m4src

       produces the output:

	       The value of VER is "".
	       VER is defined to be .

	       VER is not 2.
	       end

       The command:

	       m4 -D VER=1 m4src

       produces the output:

	       The value of VER is "1".
	       VER is defined to be 1.
	       VER is 1.
	       VER is not 2.
	       end

       The command:

	       m4 -D VER=2 m4src

       produces the output:

	       The value of VER is "2".
	       VER is defined to be 2.

	       VER is 2.
	       end

ENVIRONMENT VARIABLES

       See  environ(5)	for  descriptions  of the following environment variables that affect the execution of m4: LANG, LC_ALL, LC_CTYPE, LC_MES-
       SAGES, and NLSPATH.

EXIT STATUS

       The following exit values are returned:

       0	Successful completion.

       >0	An error occurred

       If the m4exit macro is used, the exit value can be specified by the input file.

ATTRIBUTES

       See attributes(5) for descriptions of the following attributes:

   /usr/ccs/bin/m4
       +-----------------------------+-----------------------------+
       |      ATTRIBUTE TYPE	     |	    ATTRIBUTE VALUE	   |
       +-----------------------------+-----------------------------+
       |Availability		     |SUNWcsu			   |
       +-----------------------------+-----------------------------+

   /usr/xpg4/bin/m4
       +-----------------------------+-----------------------------+
       |      ATTRIBUTE TYPE	     |	    ATTRIBUTE VALUE	   |
       +-----------------------------+-----------------------------+
       |Availability		     |SUNWxcu4			   |
       +-----------------------------+-----------------------------+
       |Interface Stability	     |Standard			   |
       +-----------------------------+-----------------------------+

SEE ALSO

       as(1), attributes(5), environ(5), standards(5)

SunOS 5.10							    19 Aug 2002 							     m4(1)