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OpenSolaris 2009.06 - man page for m4 (opensolaris section 1)

m4(1)					  User Commands 				    m4(1)

NAME
       m4 - macro processor

SYNOPSIS
       /usr/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 writes a  diagnostic  mes-
       sage 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, TABs, 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 can be rede-
       fined, 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 can 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 effectively disabled. With one argu-
		      ment,  the  left	marker	becomes the argument and the right marker becomes
		      NEWLINE. With two arguments, both markers are affected. Comment markers can
		      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 arguments are replaced by the null string; $# is replaced by
		      the number of arguments; $* is replaced by a list of all the arguments sep-
		      arated by commas; $@ is like $*, but each argument is quoted (with the cur-
		      rent 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  con-
		      catenation  of  the  streams  in numerical order. Initially 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.

       ifdef	      If  the first argument is defined, the value is the second argument, other-
		      wise 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. Otherwise, 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 argu-
		      ment 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 is 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 nullifies the effect of the
		      extra scan that is 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 argu-
		      ments, or all diversions if  no  argument.  Text	can  be  undiverted  into
		      another diversion. Undiverting discards the diverted text.

   /usr/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 numbers
	       can be specified as in C. The second argument specifies the radix for the  result;
	       the  default  is 10. The third argument	can 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 can also be specified as in C.
	       The second argument specifies the radix for the result; the  default  is  10.  The
	       third argument can be used to specify the minimum number of digits in the result.

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_MESSAGES, 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/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 5.11				    3 Jul 2007					    m4(1)


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