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 afile 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 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 ofalphanumeric 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 andSunOS 5.11 Last change: 11 Aug 2010 1
User Commands m4(1)
rescanned. OPTIONS The options and their effects are as follows:-Bint Changes the size of the push-back and argument col-
lection buffers from the default of 4,096. Values of size less than or equal to zero are ignored and the default value is used.-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. For better performance, the size should be prime. Values of size less than or equal to zero are ignored and the default value is used.-s Enables line sync output for the C preprocessor
(#line ...)
-Sint Changes the size of the call stack from the default
of 100 slots. Macros take three slots, and non-
macro arguments take one. Values of size less than or equal to zero are ignored and the default value is used.-Tint Changes the size of the token buffer from the
default of 512 bytes. Values of size less than or equal to zero are ignored and the default value is used. To be effective, the above flags must appear before any filenames and before any -D or -U flags:
-D name[=val] Defines name to val or to NULL in val's
absence.-Uname Undefines name.
OPERANDSSunOS 5.11 Last change: 11 Aug 2010 2
User Commands m4(1)
The following operand is supported: file A path name of a text file to be processed. If nofile is given, or if it is -, the standard input is
read.USAGE
The m4 utility makes available the following built-in mac-
ros. These macros can 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 can be up to fivecharacters long. changequote without argu-
ments restores the original values (that is, `'). changecom Change left and right comment markers fromthe default # and NEWLINE. With no arguments,
the comment mechanism is effectively dis-
abled. With one argument, 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 valueof the macro whose name is the first argu-
ment. Each occurrence of $n in the replace-
ment text, where n is a digit, is replaced bythe n-th argument. Argument 0 is the name of
the macro; missing arguments are replaced bythe null string; $# is replaced by the number
of arguments; $* is replaced by a list of all
the arguments separated by commas; $@ is like
$*, but each argument is quoted (with the
current quotes). defn Returns the quoted definition of itsargument(s). It is useful for renaming mac-
ros, especially built-ins.
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User Commands m4(1)
divert m4 maintains 10 output streams, numbered 0-9.
The final output is the concatenation 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, 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 argu-
ments, 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 argument is calculatedby interpreting an initial digit-string as a
decimal number.SunOS 5.11 Last change: 11 Aug 2010 4
User Commands m4(1)
index Returns the position in its first argumentwhere the second argument begins (zero ori-
gin), or -1 if the second argument does not
occur.len Returns the number of characters in its argu-
ment.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. Exam-
ple: 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 defini-
tion. 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, exceptthat it says nothing if the file is inacces-
sible. substr Returns a substring of its first argument. The second argument is a zero origin number selecting the first character; the thirdargument indicates the length of the sub-
string. A missing third argument is taken to be large enough to extend to the end of the first string.SunOS 5.11 Last change: 11 Aug 2010 5
User Commands m4(1)
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 trac-
ing 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 can beundiverted into another diversion. Undivert-
ing discards the diverted text./usr/bin/m4
eval Evaluates its argument as an arithmetic expression,using 32-bit signed-integer arithmetic. The follow-
ing 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 follow-
ing operators are supported: parentheses, unary -,
unary +, !, ~, *, /, %, +, -, <<, >>, relationals,
bitwise &, |, &&, and ||. Precedence andSunOS 5.11 Last change: 11 Aug 2010 6
User Commands m4(1)
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. endSunOS 5.11 Last change: 11 Aug 2010 7
User Commands m4(1)
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".SunOS 5.11 Last change: 11 Aug 2010 8
User Commands m4(1)
VER is defined to be 2. VER is 2. end ENVIRONMENT VARIABLES See environ(5) for descriptions of the following environmentvariables 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 occurredIf the m4exit macro is used, the exit value can be specified
by the input file.ATTRIBUTES
See attributes(5) for descriptions of the following attri-
butes:/usr/bin/m4
____________________________________________________________
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
|_____________________________|_____________________________|
| Availability | SUNWcs ||_____________________________|_____________________________|
/usr/xpg4/bin/m4
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User Commands m4(1)
____________________________________________________________
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
|_____________________________|_____________________________|
| Availability | SUNWxcu4 ||_____________________________|_____________________________|
| Interface Stability | Committed ||_____________________________|_____________________________|
| Standard | See standards(5). ||_____________________________|_____________________________|
SEE ALSO
as(1), attributes(5), environ(5), standards(5)SunOS 5.11 Last change: 11 Aug 2010 10