plucky (3) s2argv.3.gz

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>