(menu.info)Section 8.3

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Enter node , (file) or (file)node

8.3 Functions
=============

Anything matching '[a-zA-Z_]+' is taken as a function name, and an error
is generated if the function doesn't exist.  The arguments of the
functions can be other functions, string constants or variables.

prefix()
     returns the current prefix dir: either $rootprefix, or
     $HOME/$userprefix, depending on who runs install-menu

ifroot($rootarg, $userarg)
     if(getuid()==0) print $rootarg, else print $userarg

print($arg)
     Same as just $arg; if $arg is empty, generate an error.

nstring($n, $string)
     write $string $n times.  So, nstring(3,"Aa") writes "AaAaAa".
     (Useful in combination with level()).

esc($arg1,$arg2)
     Print $arg1, but escape all occurrences of characters in $arg2 with
     a '\' (thus, if arg1="hello", arg2="lo", print "he\l\l\o").

escwith($arg1, $arg2, $arg3)
     Same as esc, but use $arg3 as escape sequence.

escfirst($arg1, $arg2, $arg3)
     Same as escwith, but only escapes first occurrence of $arg2.

cppesc($arg1)
     Escape anything that isn't a letter, number or _ with
     $<hex-ascii-code>.  So, for example, a '-' is replaced by '$2D'.
     This way, $arg1 can be used as a #define in cpp.

tolower($arg)
toupper($arg)
     Returns the argument set in lowercases resp uppercases.

replacewith($s, $replace, $with)
     Search $s for occurrences of characters from string replace, and
     replace them by the corresponding character in $with.  Example:
     replacewith("hello $world, %dir", "$% ", "123") returns:
     "hello31world,32dir"

replace($s, $replace, $with)
     Search $s for occurences of $replace and replace them with $with.
     Note that the behaviour of this function is quite different than
     the replacewith() function.

ifempty($arg1, $arg2)
     If $arg1 is empty, print $arg2, otherwise print nothing.  For
     compatibility, $arg1="none" is interpreted as empty.

ifnempty($arg1, $arg2)
     If $arg1 is not empty, print $arg2.  For compatibility, the string
     "none" is seen as empty.

ifelse($arg1,$arg2,$arg3)
     If $arg1 is non-empty, print $arg2, otherwise $arg3.  For
     compatibility, the string "none" is seen as empty.

ifeq($arg1, $arg2, $arg3)
     If ($arg1==$arg2) then print $arg3

ifneq($arg1, $arg2, $arg3)
     If ($arg1!=$arg2) then print $arg3

ifeqelse($arg1, $arg2, $arg3, $arg4)
     If ($arg1==$arg2) then print $arg3 else print $arg4

cond_surr($arg1, $arg2, $arg3)
     If $arg1 is non-empty print $arg2$arg1$arg3, otherwise print
     nothing.  For compatibility, $arg1="none" is interpreted as empty.

iffile($arg1, $arg2)
     If file $arg1 exists, and can be opened for reading by whoever
     started the current process, return $arg2, otherwise return
     nothing.

ifelsefile($arg1, $arg2, $arg3)
     If file $arg1 exists, and can be opened for reading by whoever
     started the current process, return $arg2, otherwise return $arg3.

catfile($arg1)
     Return the contents of file $arg1.

shell($arg1)
     Return the output of the shell command $arg1.

forall($array, "var", $exec)
     For each element of the column separated array $array, set $var to
     that element, and print $exec.  Example:

                !include lang.h
                forall(sections_translations(), "lang", \
                   " section[" $lang "]=" translate($lang, title()) "\n")

parent($arg)
     for $arg a "directory", return parent directory:
     parent("/Debian/Applications/Editors") = "/Debian/Applications".

basename($arg)
     return the last part of the parent directory:
     basename("/Debian/Applications/Editors") = "Applications".

stripdir($arg)
     everything after the last slash, i.e.  what basename() should have
     returned: stripdir("/Debian/Applications/Editors") = "Editors".

entrycount()
     the number of entries in this menu.

entryindex()
     returns relative position of this entry.  Start with 0, last entry
     is entrycount() - 1.  BUG: if sort= anything other than $title,
     then this entryindex() will return incorrect values.

firstentry($arg)
     return $arg if this is the first entry of this menu (that is,
     entryindex() = 0).  Else, return nothing.

lastentry()
     return $arg if this is the last entry in this menu (that is,
     entryindex() = entrycount() -1).  Else, return nothing.

level()
     return nesting of this menu in the total menu tree.

add($arg1,$arg2)
sub($arg1,$arg2)
mult($arg1,$arg2)
div($arg1,$arg2)
     returns the sum, difference, product or quotient of $arg1 and
     $arg2.  Note that the arguments are strings, that are converted to
     integers.  example: mult("24", entryindex())

rcfile()
examplercfile()
mainmenutitle()
rootsection()
rootprefix()
userprefix()
treewalk()
postoutput()
preoutput()
     These functions all output whatever they were defined to be in the
     menu-method file.

translate($lang, $text)
     Translate $text into $lang using gettext, see 'forall' for an
     example.  Note that currently outputlanguage must be set to "C". If
     $lang is the empty string, $text will be translated in the current
     locale language.  See sections_translations() for a list of
     available translations.

implicit concatenation
     String constants, variables and functions can be concatenated by
     placing them after each other with a space in between, like:
     "hello" ifelse($comma, $comma, " sorry" $period " comma not
     defined") " world"