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Misc.

system string STKLOS Procedure
Sends the given string to the system shell /bin/sh. The result of system is the integer status code the shell returns.

exec str STKLOS Procedure
exec-list str STKLOS Procedure
These procedures execute the command given in str. The command given in str is passed to /bin/sh. Exec returns a strings which contains all the characters that the command str has printed on it's standard output, whereas exec-list returns a list of the lines which constitute the output of str. 
          (exec "echo A; echo B")                => "A\nB\n"
          (exec-list "echo A; echo B")           => ("A" "B")

register-exit-function! proc STKLOS Procedure
This function registers proc as an exit function. This function will be called when the program exits. When called, proc will be passed one parmater which is the status given to the exit function. The result of register-exit-function! is undefined. 
          (let* ((tmp (temporary-file-name))
                 (out (open-output-file tmp)))
            (register-exit-function! (lambda (n)
                                       (when (zero? n)
                                         (remove-file tmp))))
            out)

exit STKLOS Procedure
exit ret-code STKLOS Procedure
Exits the program with the specified integer return code. If ret-code is omitted, the program terminates with a return code of 0. If program has registerd exit functions with register-exit-function!, they are called (in an order which is the reverse of their call order).

die message STKLOS Procedure
die message status STKLOS Procedure
Die prints the given message on the current error port and exits the program with the status value. If status is omitted, it defaults to 1.

address-of obj R5RS
Returns the address of the object obj as an integer.

gc R5RS
Returns the address of the object obj as an integer.

void STKLOS Procedure
void arg1 ... STKLOS Procedure
Returns the special void object. If arguments are passed to void, they are evalued and simply ignored.

error str obj ... STKLOS Procedure
error name str obj ... STKLOS Procedure
error is used to signal an error to the user. The second form of error takes a symbol as first parameter; it is generally used for the name of the procedure which raises the error.

Note: The specification string may follow the "tilde conventions" of format (see format); in this case this procedure builds an error message according to the specification given in str. Otherwise, this procedure is conform to the error procedure defined in SRFI-23 and str is printed with the display procedure, whereas the objs are printed with the write procedure.

Hereafter, are some calls of the error procedure using a formatted string 

          (error "bad integer ~A" "a")
                               -| bad integer a
          (error 'vector-ref "bad integer ~S" "a")
                               -| vector-ref: bad integer "a"
          (error 'foo "~A is not between ~A and ~A" "bar" 0 5)
                               -| foo: bar is not between 0 and 5

and some conform to SRFI-23 

          (error "bad integer" "a")
                              -| bad integer "a"
          (error 'vector-ref "bad integer" "a")
                             -| vector-ref: bad integer "a"
          (error "bar" "is not between" 0 "and" 5)
                             -| bar "is not between" 0 "and" 5

apropos obj STKLOS Procedure
apropos obj module STKLOS Procedure
Apropos returns a list of symbols whose print name contains the characters of obj as a substring . The given obj can be a string or symbol. This function returns the list of matched symbols which can be accessed from the given module (defaults to the current module if not provided).

trace f-name ... STKLOS Syntax
Invoking trace with one or more function names causes the functions named to be traced. Henceforth, whenever such a function is invoked, information about the call and the returned values, if any, will be printed on the current error port.

Calling trace with no argument returns the list of traced functions.

untrace f-name ... STKLOS Syntax
Invoking untrace with one or more function names causes the functions named not to be traced anymore.

Calling untrace with no argument will print the list of traced functions on the current error port.

pretty-print sexpr :key port width STKLOS Procedure
pp sexpr :key port width STKLOS Procedure
This function tries to obtain a pretty-printed representation of sexpr. The pretty-printed form is written on port with lines which are no more long than width characters. If port is omitted if defaults to the current error port. As a special convention, if port is #t, output goes to the current output port and if port is #f, the output is returned as a string by pretty-print. Note that pp is another name for pretty-print.

uri-parse str STKLOS Procedure
Parses the string str as a RFC-2396 URI and return a keyed list with the following components
  • scheme : the scheme used as a string (defaults to "file")
  • host : the host as a string (defaults to "")
  • port : the port as an integer (0 if no port specified)
  • path : the path
  • query : the qury part of the URI as a string (defaults to the empty string)
  • fragment : the fragment of the URI as a string (defaults to the empty string) 
          (uri-parse "http://google.com")
              => (:scheme "http" :host "google.com" :port 80 :path "/"
                  :query "" :fragment "")
          (uri-parse "http://stklos.net:8080/a/file?x=1;y=2#end")
              => (:scheme "http" :host "stklos.net" :port 8080
                  :path "/a/file" :query "x=1;y=2" :fragment "end")
          (uri-parse "/a/file")
             => (:scheme "file" :host "" :port 0 :path "/a/file"
                 :query "" :fragment "")
          (uri-parse "")
             => (:scheme "file" :host "" :port 0 :path ""
                 :query "" :fragment "")

string->html str STKLOS Procedure
This primitive is a convenience function; it returns a string where the HTML special chars are properly translated. It can easily written in Scheme, but this version is fast. 
          (string->html "Just a <test>")
             => "Just a &lt;test&gt;"