NAME

       s2argv - convert a command string in an argv array

SYNOPSIS

       #include <unistd.h>
       #include <stdlib.h>
       #include <execs.h>

       char **s2argv(const char *args);
       void s2argv_free(char **argv);

       size_t s2argvlen(char **argv);

       size_t s2argc(char **argv);

       typedef char * (* s2argv_getvar_t) (const char *name);
       extern s2argv_getvar_t s2argv_getvar;

       These functions are provided by libexecs and libeexecs. Link with -lexecs or -leexecs.

DESCRIPTION

       s2argv  convert  a  command string in an argv array for execv(3), execvp(3) or execvpe(3).
       Single or double quotes can be used to delimitate command arguments including spaces and a
       non quoted backslash (\) is the escape character to protect the next char.
       s2argv  can  parse several commands separated by semicolons (;).  The argv of each command
       is terminated by a NULL element, one further NULL  element  tags  the  end  of  the  array
       returned by s2argv.
       s2argv  supports  variables  as  arguments. When an argument of a command is a dollar sign
       followed by a name (e.g. $USER) s2argv puts  the  output  of  the  s2argv_getvar  function
       instead.  (It  is  possible  for  example  to  assign  s2argv_getvar=getenv.  For security
       reasons, the function is NULL by default and all variables  get  replaced  with  an  empty
       string. Programmers can use their own custom function instead).

       s2argv_free frees the memory that was allocated by s2argv.

       s2argvlen returns the sum of the s2argc for all the commands, including the trailing NULLs
       that separate them.

       s2argc returns the number of arguemnts of the (first) command returned  by  s2argv.   (The
       beginning of the next argv is argv+s2argc(argv)+1).

RETURN VALUE

       s2argv  returns a dynamically allocated argv, ready to be used as an argument to execv(3),
       execvp(3) or execvpe(3).  The return value of s2argv should be  freed  by  s2argv_free  in
       case the exec command does not succeed.

EXAMPLE

       The following program demonstrates the use of s2argv:

       #include <stdio.h>
       #include <unistd.h>
       #include <stdlib.h>
       #include <execs.h>

       #define BUFLEN 1024
       int main(int argc, char *argv)
       {
            char buf[BUFLEN];
            printf("type in a command and its arguments, e.g. 'ls -l'\n");
            if (fgets(buf, BUFLEN, stdin) != NULL) {
                 char **argv=s2argv(buf);
                 execvp(argv[0], argv);
                 s2argv_free(argv);
                 printf("exec error\n");
            }
       }

SEE ALSO

       exec(3)

BUGS

       Bug reports should be addressed to <info@virtualsquare.org>

AUTHOR

       Renzo Davoli <renzo@cs.unibo.it>