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Building an argc/argv style structure from a string (char*)

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Top Forums Programming Building an argc/argv style structure from a string (char*)
# 8  
Old 12-16-2009
Hi Jim,
I actually just posted a response while you were posting that.
It's awaiting moderation because, I suppose, there is a link in it (to the source i was currently working on).

Anyway, thanks! I was looking for something like that in bash and csh source, but failed to find it! Just out of curiosity, where did you find that?

Comparing it to my parser, it appears i have re-invented a flat wheel.

-Ryan

---------- Post updated at 05:41 PM ---------- Previous update was at 05:40 PM ----------

Woops, I responded before looking through the code entirely.

Nice, you're using popen+set! This is very, very nice.

Thanks again,
-Ryan
# 9  
Old 12-17-2009
If you want to, you can use a specific shell rather than the system default shell. For example, here is how to use ksh93 via the libshell's sh_init()/sh_trap() mechanism.
Code:
#include <shell.h>
#include <stdio.h>
#include <nval.h>

int 
call_shell(int argc, char* argv[], char *str)
{
    Namval_t *np, *np_sub;
    char tmp[512];

    sprintf(tmp, "set - %s && for i in \"$@\";\n do\n aname+=(\"$i\")\ndone", str);

    Shell_t *shp = sh_init(argc, argv, 0);
    sh_trap(tmp, 0);

    np = nv_open("aname", shp->var_tree, 0);
    nv_putsub(np, NULL, ARRAY_SCAN);
    np_sub = np;

    do {
        // copy out the arguments to wherever here. 
        fprintf(stderr, "%d: subscript='%s' value='%s'\n", np_sub, nv_getsub(np_sub), nv_getval(np_sub));
    } while (np_sub && nv_nextsub(np_sub));

    nv_close(np);

    return(0);
}

int 
main(int argc, char *argv[])
{
    char string[] = "hello world 'my name is simon' foo\\ bar";

    call_shell(argc, argv, string);
}

When compiled and run, the output is
Code:
... value='hello'
... value='world'
... value='my name is simon'
... value='foo bar'

# 10  
Old 12-17-2009
I like fpMurphy's approach better, but shells support
Code:
set -  parm1 parm2 parm3

as a way to redefine the parameters for the current invocation. This just uses the shell's built in parser. You can change behavior of the parser by defining the IFS variable.
# 11  
Old 12-17-2009
Quote:
I like fpMurphy's approach better
Thanks Jim. However it is not for the fainthearted. You have to know the internal structures of whichever shell you choice to use.
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