/* $OpenBSD: autoexec.c,v 1.19 2023/03/08 04:43:11 guenther Exp $ */
/* this file is in the public domain */
/* Author: Vincent Labrecque <vincent@openbsd.org>      April 2002 */

#include <sys/queue.h>
#include <fnmatch.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "def.h"
#include "funmap.h"

struct autoexec {
        SLIST_ENTRY(autoexec) next;     /* link in the linked list */
        const char      *pattern;       /* Pattern to match to filenames */
        PF               fp;
};

static SLIST_HEAD(, autoexec)    autos;
static int                       ready;


#define AUTO_GROW 8
/*
 * Return a NULL terminated array of function pointers to be called
 * when we open a file that matches <fname>.  The list must be free(ed)
 * after use.
 */
PF *
find_autoexec(const char *fname)
{
        PF              *pfl, *npfl;
        int              have, used;
        struct autoexec *ae;

        if (!ready)
                return (NULL);

        pfl = NULL;
        have = 0;
        used = 0;
        SLIST_FOREACH(ae, &autos, next) {
                if (fnmatch(ae->pattern, fname, 0) == 0) {
                        if (used >= have) {
                                npfl = reallocarray(pfl, have + AUTO_GROW + 1,
                                    sizeof(PF));
                                if (npfl == NULL)
                                        panic("out of memory");
                                pfl = npfl;
                                have += AUTO_GROW;
                        }
                        pfl[used++] = ae->fp;
                }
        }
        if (used)
                pfl[used] = NULL;

        return (pfl);
}

int
add_autoexec(const char *pattern, const char *func)
{
        PF               fp;
        struct autoexec *ae;

        if (!ready) {
                SLIST_INIT(&autos);
                ready = 1;
        }
        fp = name_function(func);
        if (fp == NULL)
                return (FALSE);
        ae = malloc(sizeof(*ae));
        if (ae == NULL)
                return (FALSE);
        ae->fp = fp;
        ae->pattern = strdup(pattern);
        if (ae->pattern == NULL) {
                free(ae);
                return (FALSE);
        }
        SLIST_INSERT_HEAD(&autos, ae, next);

        return (TRUE);
}

/*
 * Register an auto-execute hook; that is, specify a filename pattern
 * (conforming to the shell's filename globbing rules) and an associated
 * function to execute when a file matching the specified pattern
 * is read into a buffer.
*/
int
auto_execute(int f, int n)
{
        char    patbuf[BUFSIZE], funcbuf[BUFSIZE], *patp, *funcp;
        int     s;

        if ((patp = eread("Filename pattern: ", patbuf, sizeof(patbuf),
            EFNEW | EFCR)) == NULL)
                return (ABORT);
        else if (patp[0] == '\0')
                return (FALSE);
        if ((funcp = eread("Execute: ", funcbuf, sizeof(funcbuf),
            EFNEW | EFCR | EFFUNC)) == NULL)
                return (ABORT);
        else if (funcp[0] == '\0')
                return (FALSE);
        if ((s = add_autoexec(patp, funcp)) != TRUE)
                return (s);
        return (TRUE);
}