Provided by: icmake_12.00.01-1ubuntu1_amd64 
NAME
icmscript - The C-like icmake scripting language
DESCRIPTION
Icmake(1) is a generic tool handling program maintenance that can be used as an
alternative for make(1). It’s a generic tool in that icmake-scripts, written in a language
closely resembling the C programming language, can perform tasks that are traditionally
the domain of scripting languages.
Icmake allows programmers to use a programming language (closely resembling the
C-programming language) to define the actions that are required for (complex) program
maintenance. For this, icmake offers various special operators as well as a set of support
functions that have shown their usefulness in program maintenance.
This man-page covers the icmake scripting language in de following sections:
o DATA TYPES
- int, list, string, and void (for functions);
o OUTLINE
- outline of icmake scripts: what are their requirements, the structure and
organization of their main-functions.
o PREPROCESSOR DIRECTIVES
- supported preprocessor directives, like #include and #define;
o PREDEFINED CONSTANTS
- like O_FILE, OFF, and S_IFREG;
o OPERATORS
- like +, younger, and casts
o FLOW CONTROL
- if, for, while, etc. (the switch is not available);
o PREDEFINED FUNCTIONS
- executing programs, changing directories, operations on string and list type
variables, etc.. Functions are marked as INT FUNCTIONS, LIST FUNCTIONS, STRING
FUNCTIONS
o USER DEFINED FUNCTIONS
- at least main, with or without its common parameters argc, argv, and envp.
DATA TYPES
Icmake supports the following five data and value types:
o ASCII character constants
ASCII character constants are ascii-characters, surrounded by single or double
quotes. Single characters (e.g., ’a’) represent the character itself. Standard
escape sequences (e.g., ’\n’) are supported and are converted to their well-known
values (e.g., ’\n’ represents ascii value 10 (decimal)). Non-standard escape
sequences (e.g., ’\x’) are converted to the ascii character following the escape
character (so ’\x’ equals ’x’). Escaped sequences consisting of three octal digits
represent the ascii character corresponding to the octal value, modulo 256 (e.g.,
’\113’ represents ’K’). Escape sequences consisting of an x followed by two
hexadecimal digits represent the ascii character corresponding to the hexadecimal
value (e.g., ’\x4b’, also representing ’K’);
o int
Integral values, ranging from -0x8000 through 0x7fff. int constants may be
specified as decimal numbers (starting with digits 1 through 9), octal numbers
(starting with 0, followed by one or more octal digits), hexadecimal numbers
(starting with 0x, followed by one or more hexadecimal digits), or as ASCII
character constants;
o string
Text values: text (or `string’) constants are delimited by double quotes. Multiple
string constants may be concatenated, but a single string constant may not span
multiple lines. Multiple string constants, only separated by white space (i.e.,
blanks, newlines, comment) are concatenated and are considered one single string
constant. To indicate an end-of-line in a string constant use the \n escape
sequence;
If arithmetic expressions use at least one int operand then those expressions may
also contain single character ASCII constants using double quotes. In those cases
they represent the ascii-values of their characters.
Conversely, ASCII character constants using single quotes may be used in situations
where string operands are expected;
o list
A list is a data structure containing a series of individually accessible string
values. When a list contains elements, its first element has index 0;
Lists may be written to the standard output stream or to file (using printf or
fprintf). Lists can also be inserted into string variables using strformat. In
these cases all (space delimited) elements of the lists are inserted into their
destinations;
Lists can also be defined as constants. They consist of an optional series of comma
separated string constants surrounded by a pair of square brackets. E.g.,
list words = ["a", "list", "constant"];
o void
The type void is used when defining functions to indicate that such functions do
not return values. Alternatively, functions may return int, string or list values
(cf. section USER DEFINED FUNCTIONS).
Variables can be defined at the global level inside functions (not only at the top of
compound statements but also between statements and in the initialization section of for-
and if-statements). When defined inside functions, the standard C scoping and visibility
rules apply. Variables are strongly typed, and cannot have type void.
Variables may be initialized when they are defined. Initializations are expressions which
may use predefined or user-defined functions, constant values, and values of variables.
Functions or variables that are used for initialization must be visible at the
initialization point.
OUTLINE
Icmake scripts require a user-defined function main. The function main has three optional
parameters, which may be omitted from the last one (envp) to the first one (argc), like in
C. Its full prototype is:
void main(int argc, list argv, list envp)
or
int main(int argc, list argv, list envp)
When a void main function ends (using a return; statement or when its execution reaches
its body’s closing curly) the value 0 is returned to the operating system. When int main
functions end using return statements then those statements must be provided with
int-expressions. It’s OK when the execution of an int main function reaches its body’s
closing curly, om which case 0 is automatically returned to the operating system
In main the parameter
o argc represents the number of elements in argv;
o argv contains the arguments, with element 0 being equal to the name of the .bim
file, that were passed to the .bim file. The OPTIONS section of the icmake(1)
manpage covers how these arguments are forwarded to the icmake script using options
-e, -s, and -t.
o envp contains the `environment’ variables. The (predefined) function listlen can be
used to determine the number of its elements. Elements in envp use the format
variable=value. Alternatively, the (predefined) function getenv can be used to
retrieve a specific environment variable immediately.
Example (the implementations of the user-defined functions usage, modified, and compile
are left as an exercise for the reader):
void main(int argc, list argv)
{
if (argc == 1)
usage(argv[0]);
if (list toCompile = modified("*.cc"))
{
for (int idx = listlen(toCompile); idx--; )
compile(toCompile[idx]);
}
}
When executing an icmake script icmake’s run-time support system first initializes all all
global variables in the order of their definitions. Followin this the function main is
called. The script ends once main returns or when the (predefined) function exit is called
by the script.
PREPROCESSOR DIRECTIVES
Before actually compiling icmake scripts they are first pre-processed by the icmake
pre-processor. The pre-processor removes comment, includes files specified by
include-directives, and processes #define and comparable directives.
The following preprocessor directives are recognized:
o comment:
standard C comment (everything from /* through */) as well as
comment-to-end-of-line (starting at //, continuing to the end of the line) is
ignored;
o Shell startup: The first line of the icmake-script may start with #!path, where
path defines the absolute location of the icmake program. By making the script
executable, it can be called without explicitly calling icmake.
E.g., if the first line of an (executable) icmakefile ’icm’ (without extension)
contains
#!/usr/bin/icmake -t.
then icm can be issued as a command, interpreting the remaining content of the
script as an icmake source which is compiled and then executed by icmake. In these
cases the binary files are removed when the scipts end;
o #include "filename"
The file filename is included at the location of the directive;
o #include <filename>
The file filename is included at the location of the #include directive; filename
is searched in the colon-separated directories specified by the IM environment
variable. The first occurrence of filename in the directories specified by the IM
environment variable is used;
o #define identifier [definition]
The text identifier is replaced by definition. The definition may contain
references to already defined identifiers, using the format ${identifier}. If the
${identifier} hasn’t been defined (yet), the literal text ${identifier} is used. To
prevent infinite recursion at most 100 ${identifier} replacements are accepted;
If the last character on a line is a backslash (\) then definitions continue at the
next line. (the backslash is not included in the definition). The preprocessor
concatenates double-quoted strings. Double quoted strings may not span multiple
lines. Multiple blanks (outside of double quoted strings) in definitions are
contracted to a single blank space;
Following the #define’s identifier a definition may optional be provided. If
omitted, the macro is defined, so it can be used in #if(n)def directives (see
below), but in those cases these intentifiers are simply removed from icmake code
statements.
o #ifdef identifier
If the identifier macro was defined the next block of code (until a matching #else
or #endif directive was read) is byte-compiled. Otherwise, the block of code is
ignored;
o #ifndef identifier
If the identifier macro was not defined the next block of code (until a matching
#else or #endif directive was detected) is byte-compiled. Otherwise, the block of
code is ignored;
o #else
Terminates #ifdef and #ifndef directives, reversing the acceptance decision about
the following code. Only one #else directive can be associated with #if(n)def
directives;
o #endif
Terminates the preprocessor block starting at the matching #ifdef, #ifndef or #else
directive. The #endif directory and its matching #if(n)def directive must be
specified in the same file;
o #undef identifier
Remove identifier from the set of defined symbols. This does not affect the
specification of any previously defined symbols in which identifier’s definition
has been used. If identifier hasn’t been defined a warning is issued.
PREDEFINED CONSTANTS
The following predefined int constants are available (the functions listed in the intended
for column are described in the upcoming sections covering the predefined functions):
─────────────────────────────────
symbol value intended for
─────────────────────────────────
O_ALL 8 makelist
O_DIR 2 makelist
O_FILE 1 makelist
O_SUBDIR 4 makelist
─────────────────────────────────
OFF 0 echo
ON 1 echo
─────────────────────────────────
P_CHECK 0 system calls
P_NOCHECK 1 system calls
─────────────────────────────────
S_IEXEC 32 stat
S_IFCHR 1 stat
S_IFDIR 2 stat
S_IFREG 4 stat
S_IREAD 8 stat
S_IWRITE 16 stat
─────────────────────────────────
The following constants are architecture dependent:
──────────────────────────────────────────────────────────────
symbol 1 when defined on the platform, otherwise 0
──────────────────────────────────────────────────────────────
unix Unix, usually with GNU’s gcc compiler
UNIX may alternatively be available
linux x86 running Linux (usually with gcc)
LINUX may alternatively be available
M_SYSV, M_UNIX x86 running SCO/Unix
_POSIX _SOURCE Unix with Posix compliant compiler
__hpux HP-UX, with the native HP compiler
──────────────────────────────────────────────────────────────
OPERATORS
Since icmake version 10.00.00 the << operator can be used like the C++ insertion operator.
See the description of the functions printf and fprintf below.
int-operators:
All C operators (including the ternary operator) are available (except for pointer
operators, as icmake does not support pointers). They operate like their C-programming
language’s counterparts. Comparison operators return 1 if the comparison is true,
otherwise 0 is returned.
string-operators:
For string variables and/or constants the following operators are available (lhs and rhs
are string variables or constants):
o lhs + rhs: returns a new string value containing the concatenation of strings lhs
and rhs. Note that string constants can also directly be concatetated (not using
the + operator), e.g., the following two lines both define the string "hello
world":
"hello " "world"
"hello " + "world"
o lhs += rhs: lhs must be a string variable, to which the string variable or value
rhs is appended;
o string comparisons: operators == != <= >= < > != and == return 1 if the comparison
is true, otherwise 0. The ordering operators (like < and >=) use the (case
sensitive) character ordering defined by the ASCII character set;
o !lhs: the boolean ! (not) operator returns 1 if the string lhs is empty, otherwise
0 is returned. Strings containing white-space characters are not empty;
o lhs younger rhs, lhs newer rhs: returns 1 if file lhs is more recent than file rhs.
E.g., "source.cc" newer "source.o". The files lhs and rhs do not have to exist:
o if both don’t exist 0 is returned,
o if lhs doesn’t exist 0 is returned,
o if rhs doesn’t exist, 1 is returned,
o if they are equally old 0 is returned.
The predefined function exists() (see below, section PREDEFINED FUNCTIONS) can be
used to test whether a file exists;
o lhs older rhs: returns 1 if file lhs is older than file rhs. E.g., "libprog.a"
older "source.o". The files lhs and rhs do not have to exist:
o if both don’t exist 0 is returned,
o if lhs doesn’t exist 1 is returned,
o if rhs doesn’t exist, 0 is returned,
o if they are equally old 0 is returned.
o []: the index operator returns a character from a string variable or constant. A
string is returned as an rvalue. Thus, the following statement compiles OK:
lhs = rhs[3];
but the following statement won’t compile:
lhs[3] = "a";
If an invalid (out of bounds) index value is specified an empty string is returned.
o The backtick operator (`string cmd`)
A string placed between two backticks is executed as a separate command. Different
from the exec and system calls the backtick operator collects the standard output
produced by `cmd’ returning this output as a list.
The elements of the list contain the subsequent lines of output (including a final
newline, if present) produced by `cmd’. A command that could be executed but that
did not produce any output returns a list containing one string element, which is
empty.
An empty list indicates that the command could not be executed.
The command’s standard error stream output is ignored by the backtick operator.
However, standard shell redirection may be used to collect the standard error
stream’s output.
Example:
printf << `"ls"`; // prints the elements in
// the current directory
Also note that the backtick operator requires a string argument: either a string
constant or a string variable.
The predefined function eval(string cmd) behaves exactly like the backtick
operator: they are synonyms.
list-operators:
For list variables and/or values the following operators are available:
o lhs + rhs: returns a new list value containing the concatenation of the values of
lists lhs and rhs. This is not a set operation: if an element appears both in lhs
and in rhs, then both will appear in the resulting list (set-addition is provided
by the built-in function listunion);
o lhs - rhs: returns a new list value containing the elements in lhs that are not
present in rhs. This is a set-difference operation. The ordering of the remaining
elements in the returned list is equal to the ordering of those elements in lhs;
o lhs += rhs: elements in rhs are added to the elements in lhs, which must be a list
variable. This is not a set operation;
o lhs -= rhs: elements in rhs are removed from the elements in lhs. This is a set
operation: all elements of lhs that are found in rhs are removed from lhs. The
ordering of the remaining elements in lhs is not altered;
o list equality comparisons: operators != and == may be applied to list values or
variables. Operator == returns 1 if both lists have element-by-element identical
elements, otherwise 0 is returned. Operator != reverses the result of ==;
o !lhs: the boolean ! operator returns 1 if the list lhs is empty, otherwise 0 is
returned;
o []: the index operator retrieves an element from a list variable: it returns a
string as an rvalue. Thus, the following statement compiles OK:
// assume lst is a list, str is a string
str = lst[3];
but the following statement won’t compile:
lst[3] = str;
If an invalid (out of bounds) index value is specified an empty string is returned.
Casting:
Type-casts using the standard C-style cast-operator can be used to cast:
o strings to ints and vice versa ((int)"123", (string)55)
If the content of a string does not represent a (decimal) int value 0 the cast
returns 0;
o Strings to lists (list lst = (list)"hello"): this returns a list having one element
(hello) (note that casting a string to a list as shown is overkill as list lst =
["hello"] performs the same initialization).
FLOW CONTROL
Icmake offers a subset of C’s flow control statements. They can be used as in the C
programming language.
o expression ;
The plain expression statement.
Insert-expression statements are defined for the functions fprintf and printf.
Expression statements may start with printf << or fprintf << filename <<. The
values of all subsequent expressions, separated by << operators (which in this
context are called insertion operators) are written to the standard output stream
(when using printf <<), or to the file whose name is provided in the string
filename (when using fprintf << filename <<). Examples:
printf << "hello" << ’ ’ << "world" << ’\n’;
fprintf << "out.txt" << "hello" << ’ ’ << "world" << ’\n’;
o The compound statement
Variables may be defined and initialized inside compound statements at locations
where expression statements can also be used. The visibility of variables starts at
their points of definition;
o if ([definition;] condition) statement
The [definition;] phrase is optional. If used it defines a type followed by a
comma-separated list of variables which may be provided with initialization
expressions.
The condition phrase is required, and may define and initialize a variable. E.g,
if (string str = getText())
process(str);
In this example, process is not called if getText() returns an empty string.
Variables defined in the definition and condition phrases do not exist either
before or after the if statement.
o if ([definition;] condition) statement1 else statement2
Acts like the previous statement. If the condition is true statement1 is executed;
if the condition is false statement2 is executed;
o for (init; condition; increment) statement
Variables (of a single type) may be initialized (and optionally defined) in the
init section. The condition phrase may define and initialize a variable. The init,
condition and increment sections may remain empty. An empty condition section is
interpreted as `always true’;
o while (condition) statement
Inside the condition a variable may be defined and initialized.
A complementary do ... while() statement is not available. Note that when a
variable is defined and initialized in the condition section the initialization
expression is executed at each iteration of the while statement. Thus the following
statement never ends, and displays a never ending stream of values 10:
while (int x = 10)
printf(x--, "\n");
o return;, and return expression;
Plain return statements can be used in void functions, and return expression
statements are used in other type of functions.
o break
break; statements can only be used in for and while statements, ending those
statements;
o continue
continue; statements can only be used in for and while statements, continuing their
next iteration.
PREDEFINED FUNCTIONS
Icmake provides the following predefined functions, which can be used anywhere in icmake
scripts. In the following overview the functions are ordered by categories, and within
categories they are ordered alphabetically by function name.
Five categories are distinguished:
o Functions operating on ints (see INT FUNCTIONS below):
these functions receive int arguments, processing those arguments;
o Functions operating on strings (see STRING FUNCTIONS below):
these functions operate on the strings which are passed to these functions as
arguments;
o Functions operating on lists (see LIST FUNCTIONS below):
these functions operate on the lists which are passed to these functions as
arguments;
o Functions manipulating file system entries (see FILESYSTEM FUNCTIONS below):
these functions receive the names of file-system entries (files, directories, etc.)
as their string arguments.
Note that these functions are not listed in the STRING FUNCTIONS section, as they
do not directly operate on their string arguments, but merely use those arguments
to identify file system entries.
On the other hand, functions like change_base do not operate on file-system entries
and are therefore entries in the STRING FUNCTIONS section;
o System-related functions (see SYSTEM FUNCTIONS below):
these functions interface to facilities provided by the operating system, like
executing programs or changing the script’s environment variables. Some of these
functions use specialized support functions, which are also included in this
section.
INT FUNCTIONS:
o string ascii(int value)
returns value as a string: ascii(65) returns the string "A";
o echo(int opt)
controls echoing of called programs (and their arguments), specify OFF if echoing
is not requested. By default echo(ON) is active.
STRING FUNCTIONS:
o int ascii(string str)
returns the first character of str as an in: ascii("A") returns 65;
o string change_base(string file, string base)
returns file whose base name is changed into base: change_base("/path/demo.im",
"out") returns "/path/out.im";
o string change_ext(string file, string ext)
returns file whose extension is changed into ext: change_ext("source.cc", "o")
returns "source.o". The extension of the returned string is separated from the
file’s base name by a single dot (e.g., change_ext("source.", ".cc") returns
"source.cc");
o string change_path(string file, string path)
return file whose path is changed into path: change_path("tmp/binary", "/usr/bin")
returns "/usr/bin/binary". To remove the path specify path as an empty string;
o string element(int index, string var)
acts identically to the index operator: refer to the index ([]) operator in section
OPERATORS;
o string get_base(string file)
returns the base name of file. The base name is the file without its path prefix
and without its extension. The extension is all information starting at the final
dot in the filename. If no final dot is found, the file name is the base name.
E.g., the base name of a.b equals a, the base name of a.b.c equals a.b, the base
name of a/b/c equals c;
o string get_dext(string file)
returns the extension of file, including the separating dot (hence the d in dext).
The extension is all information starting at the filename’s final dot. If file does
not have a final dot then an empty string is returned;
o string get_ext(string file)
returns the extension of file, without the separating dot. The extension are all
characters in file starting at file’s final dot. If no final dot is found, an empty
string is returned;
o string get_path(string file)
returns file’s path-prefix. The path prefix is all information up to (and
including) the final directory separator (which is, depending on the operating
system, a forward slash or a backslash). If file does not contain a path-element,
then an empty string is returned;
o string resize(string str, int newlength) returns a copy of string str, resized to
newlength characters. If newlength is negative then an empty string is returned,
if newlength exceeds str’s length then the newly added characters are initialized
to blank spaces;
o int strchr(string str, string chars)
returns the first index in str where any of the characters in chars is found, or -1
if str does not contain any of the characters in chars;
o int strfind(string haystack, string needle)
returns index in haystack where needle is found, or -1 if needle is not found in
haystack;
o string strformat(string format, argument(s))
returns a string constructed from the format string containing placeholders %1 ..
%2 to refer to arguments following the format string. The specification %1 refers
to the first argument following the format string. If fewer arguments than n are
provided then additional 0 arguments are provided by icmake. Example:
void main()
{
string s2 = = strformat("%1 %2 %1\n", 10, 20);
printf("s2 = ", s2); // shows: s2 = 10 20 10
}
o int strlen(string str)
returns the number of characters in str (not counting the terminating
NUL-character);
o string strlwr(string str)
returns a lower-case duplicate of str;
o list strtok(string str, string separators)
returns a list containing all substrings of str separated by one or more
(consecutive) characters in separators: strtok("hello icmake’s+world", " +")
returns a list containing the three strings "hello", "icmake’s", and "world";
o string strupr(string str)
returns an upper-case duplicate of str.
o string substr(string text, int offset, int count)
returns a substring of text, starting at offset, consisting of count characters. If
offset exceeds (or equals) the string’s length or if count <= 0, then an empty
string is returned. If offset is less than 0 then offset = 0 is used. If offset +
count exceeds text’s length then the available substring starting at text[offset]
is returned (which may be empty);
o string trim(string str)
returns a copy of str without leading and trailing white spaces;
o string trimleft(string str)
returns a copy of str without leading white spaces;
o string trimright(string str)
Returns a copy of str without trailing white spaces.
LIST FUNCTIONS:
o string element(int index, list var)
acts identically to the index operator: refer to the index ([]) operator in section
OPERATORS;
o int listfind(list lst, string str)
returns the smallest index in lst where the string str is found, or -1 if lst does
not contain str;
o int listlen(list l)
returns the number of elements in list;
o list listunion(list lhs, list rhs)
returns a list containing the union of the elements in lhs and the elements of rhs.
The original order of the elements in lhs is kept. Subsequent elements in rhs that
are not available in lhs are added to the end of lhs;
o list listunion(list lst, string str)
returns a list containing the union of the elements in lst and str. The original
order of the elements in lhs is kept. If rhs is not available in lhs then it is
added to the end of lhs.
FILESYSTEM FUNCTIONS:
o string chdir([int check,] string dir)
changes the script’s working directory to dir (which may be specified as absolute
or relative to the script’s current working directory). The first argument is
optional: if omitted and changing the working directory fails then the
icmake-script ends with exit value 1; by specifying P_NOCHECK the function won’t
terminate the script but merely returns the script’s current working directory. The
script’s working directory after completing the change-dir request is returned as
an absolute path, ending in a `/’ directory separator.
Use chdir(".") to merely obtain the current working directory; use chdir("") to
change-dir to the script’s startup working directory;
o int exists(string file)
if file exists, 1 is returned, otherwise 0 is returned;
o list fgets(string file, list offset)
the next line found at offset value offset[3] is read from file. Pass an empty list
to fgets to read file from its beginning.
The returned list has four elements:
o its first element ([0]) contains the read line (without the line’s \n line
terminator);
o its second element ([1]) contains the line’s \n line terminator (or an empty
string if the line was not terminated by a \n);
o its third element ([2]) contains the string OK if the line was successfully
read and FAIL if reading from file failed;
o its fourth element ([3]) contains the offset beyond the last read byte.
To read multiple lines, pass the returned list as argument to fgets:
list ret;
while (ret = fgets("filename", ret))
process(ret);
Be careful not to define list ret in while’s condition, as this will reset ret to
an empty list at each iteration;
o int fprintf(string filename, argument(s))
appends all (comma or left-shift (insertion) operator separated) arguments to the
file filename. Returns the number of printed arguments.
If the first argument (following filename) contains placeholders (%1, %2, ... %n)
then that argument is considered a format string (see also the function strformat
in the string functions section for additional information about format strings).
Some examples:
fprintf("out", "hello", "world", ’\n’);
fprintf << "out" << "hello" << "world" << ’\n’;
fprintf("out", "%1 %2\n", "hello", "world"); // 1
fprintf << "out" << "hello" << ’ ’ << "world" << ’\n’; // 2
fprintf << "out" << "%1 %2\n" << "hello" << "world"; // 3
When writing statement 1 using insertion operators (cf. the expression statement
description in section FLOW CONTROL) statement 2 would normally be encountered,
although statement 3, using the format string, would still be accepted;
o string getch()
returns the next pressed key as a string (pressing the `Enter’-key is not
required). The pressed key is not echoed. If the key should be echoed use, e.g.,
printf(getch());
o string gets()
returns the next line read from the keyboard as a string. The line contains all
entered characters until the `Enter’-key was pressed. The `Enter’-key’s value
itself is not stored in the returned string;
o list makelist([int type = O_FILE], string mask)
the argument type is optional, in which case O_FILE is used. Makelist returns a
list of all type file-system entries matching mask. E.g., makelist("*.c") returns a
list containing all files ending in .c. For type one of the following set of values
can be used to obtain a more specific selection of directory entries:
symbol meaning
O_ALL obtain all directory entries
O_DIR obtain all directories, including . and ..
O_FILE obtain a list of regular files
O_SUBDIR obtain all directories except for . and ..
In Unix-type operating systems the pattern * does not match entries starting with a
dot (hidden entries). To obtain a list of such entries use the pattern .*;
o list makelist([int type = O_FILE,] string mask, {newer,older,younger}, string
comparefile)
the (optional) parameter type may be specified as in the previous variant of
makelist. The third parameter must be either newer (or younger) or older. A list of
all file-system entries matching mask which are, resp., newer or older than a
provided comparefile is returned. Note that newer and younger are operators, not
strings;
o int printf(argument(s))
the function’s (comma or left-shift (insertion) operator separated) arguments are
written to the standard output file (cf. the expression statement description in
section FLOW CONTROL and this section’s description of the fprintf function). If
the first argument contains %1, %2, ... %n specifications then it’s considered a
format string (see also the function strformat in the STRING FUNCTIONS section for
additional information about format strings). Like fprintf printf returns the
number of printed arguments;
o list stat([int check,] string entry)
Returns stat(2) information of directory entry entry as a list. The first argument
is optional: if omitted and calling the system stat function fails then the
icmake-script ends with exit value 1; by specifying P_NOCHECK the function won’t
terminate the script but returns the return value (-1) of the system stat function.
The returned list has two elements:
its first element ([0]) holds the entry’s attributes. Attributes are returned as
the file type and mode of the specified file (cf. stat(2) and inode(7)). E.g.,
S_IRUSR - owner has read permission
S_IWUSR - owner has write permission
S_IXUSR - owner has execute permission
S_IFSOCK - socket
S_IFLNK - symbolic link
S_IFREG - regular file
S_IFBLK - block device
S_IFDIR - directory
S_IFCHR - character device
S_IFIFO - FIFO
its second element ([1]) contains the entry’s size in bytes. If P_NOCHECK was
specified and ’entry’ doesn’t exists then a list having one element is returned
containing -1.
SYSTEM FUNCTIONS:
o void arghead(string str)
support function of exec() (see also below at exec()): defines the `argument head’
that is used with exec(). By default, the `argument head’ is an empty string. The
argument head is text that is prefixed to all exec arguments, like a directory in
which provided arguments are found;
o void argtail (string str)
support function of exec() (see also below at exec()): defines the `argument tail’
that is used with exec(). By default, the `argument tail’ is an empty string. The
argument tail is text that is appended to all exec arguments, like the extensions
of files that are passed as arguments to exec;
o cmdhead(string str)
support function of exec() (see also below at exec()). Defines a `command head’
that is used with exec(). By default it is an empty string. It can be used to
specify, e.g., compiler options when the arguments themselves are modified by
arghead and argtail. The cmdhead argument itself is not modified by arghead or
argtail;
o cmdtail(string str)
support function of exec() (see also below at exec()). Defines a `command tail
that is used with exec(). By default it is an empty string. It can be used to
specify a final argument (not modified by arghead and argtail);
o list eval(string str)
this function can be used instead of the backtick operator (cf. section OPERATORS).
The example provided with the backtick operator could therefore also have been
written like this:
printf << eval("ls"); // prints the elements in the current
// directory
As mentioned at the backtick operator: the elements of the list contain the
subsequent lines of output (including a final newline, if present) produced by
`cmd’. A command that could be executed but that did not produce any output returns
a list containing one string element, which is empty.
An empty list indicates that the command could not be executed.
o int exec([int check,] string cmd, argument(s))
Executes the command cmd with (optional) arguments. Each argument is prefixed by
arghead and postfixed by argtail. Note that no blanks are inserted between arghead,
argument(s), and argtail. The thus modified arguments are concatenated, separated
by single blanks. Cmdhead is inserted between cmd and the first argument (delimited
by single blanks) and cmdtail is appended to the arguments, separated by a single
blank. PATH is searched to locate cmd. 0 is returned.
The first argument is optional: if omitted and the command does not return 0 the
icmake script terminates. By specifying P_NOCHECK exec won’t terminate the script
but returns the called command’s exit status, or 0x7f00 if the command wasn’t
found.
The remaining arguments may be ints, strings or lists. Int and list arguments are
cast to strings. Their string representations are then appended to cmd;
o int execute([int checking,] string cmd, string cmdhead, string arghead,
argument(s), string argtail, string cmdtail)
Same functionality as the previous function, but the cmdhead, arghead, argtail, and
cmdtail are explicitly specified (and are reset to empty strings after executing
cmd);
o exit(expression)
Ends the execution of an icmake-script. The expression must evaluate to an int
value, which is used as the script’s exit value;
o list getenv(string envvar)
returns the value of environment variable envvar in a list containing two elements:
if the first element ([0]) is "1" then the environment variable was defined;
environment variables are of the form variable=value. If element [0] is "1" then
the returned list’s second element [1] holds the value part of the environment
variable, which is empty if the environment variable is merely defined;
o int getpid()
returns the process-id of the icmake byte code interpreter icm-exec;
o int putenv(string envvar)
adds or modifies envvar to the current icmake-script environment. Use the format:
"VAR=value". Use "VAR" to remove "VAR" from the environment. The function returns 0
unless envvar is empty, in which case 1 is returned;
o int system([int check,] string command)
executes command using the system(3) function. The first argument is optional: if
omitted and calling the system(3) function does not return 0 then the icmake-script
ends with exit value 1; by specifying P_NOCHECK icmake’s system function won’t
terminate the script but returns the return value of the system(3) function
(normally the executed command’s exit value). The string command may use
redirection and/or piping.
USER DEFINED FUNCTIONS
In addition to main additional functions are usually defined. Once defined, they can be
called. Forward referencing of either variables or functions is not supported, but calling
functions recursively is. As function declarations are not supported indirect recursion
cannot be used.
User-defined functions must have the following elements:
o The function’s return type, which must be void, int, string or list. There is no
default type;
o The function’s name, e.g., compile;
o A parameter list, defining zero or more comma-separated parameters. The parameters
themselves consist of a type name (int, string, or list) followed by the
parameter’s identifier. E.g., (string outfile, string source);
o A body surrounded by a pair of curly braces ({ and }).
Function bodies may contain variable definitions (optionally initialized at their
definitions). Variable definitions start with a type name, followed by one or more comma
separated and optionally initialized variable identifiers.
If a variable is not explicitly initialized it is initialized by default: int variables
are initialized to 0, string variables are initialized to empty strings ("") and list
variables are initialized to empty lists.
Function bodies may also contain zero or more statements (cf. section FLOW CONTROL). Note
that variables may be defined (and optionally initialized) anywhere inside functions where
expression statements can be used, and also in the condition sections of if, for, and
while statements and in the initialization sections of if andd for statements.
EXAMPLE
In the following example all C++ source files in the current directory are compiled unless
their object files are more recent. The main function creates a list of source files and
then passes each of them to a function inspect. That function inspects whether the source
file is younger than its object file, and if so it calls compile. The function compile
uses exec to call the compiler. If a compilation fails the script stops so the error can
be repaired. Source files for which the compilation succeeded are not recompiled when the
script is rerun. Assuming the script is named compile.im then it can be called using
icmake -s compile.im. This also creates compile.bim, so after the -s call the command
icmake -e compile.bim can be used to immediately execute the bim-file:
void compile(string src)
{
exec("g++ -c " + src); // compile ’src’
}
void inspect(string src)
{ // get the obj-file’s name:
// only compile if necessary
if (src younger change_ext(src, ".o"))
compile(src);
}
int main()
{ // find all .cc source files
list sources = makelist("*.cc");
for ( // visit all source files
int idx = 0, end = listlen(sources);
idx != end;
++idx
)
inspect(sources[idx]); // compile if needed
}
SEE ALSO
icmake(1), icmbuild(1), icmconf(7), icmstart(1), icmstart.rc(7)
BUGS
Standard comment starting on lines containing preprocessor directives may not extend over
multiple lines.
Path names containing blanks are not supported.
COPYRIGHT
This is free software, distributed under the terms of the GNU General Public License
(GPL).
AUTHOR
Frank B. Brokken (f.b.brokken@rug.nl).