sudoers.c

static char *
resolve_editor(const char *ed, size_t edlen, int nfiles, char **files, int *argc_out, char ***argv_out)
{
    char *cp, **nargv, *editor, *editor_path = NULL;
    int ac, i, nargc;
    bool wasblank;
    debug_decl(resolve_editor, SUDOERS_DEBUG_PLUGIN)

    /* Note: editor becomes part of argv_out and is not freed. */
    editor = sudo_emalloc(edlen + 1);
    memcpy(editor, ed, edlen);
    editor[edlen] = '\0';

    /*
     * Split editor into an argument vector; editor is reused (do not free).
     * The EDITOR and VISUAL environment variables may contain command
     * line args so look for those and alloc space for them too.
     */
    nargc = 1;
    for (wasblank = false, cp = editor; *cp != '\0'; cp++) {
	if (isblank((unsigned char) *cp))
	    wasblank = true;
	else if (wasblank) {
	    wasblank = false;
	    nargc++;
	}
    }
    /* If we can't find the editor in the user's PATH, give up. */
    cp = strtok(editor, " \t");
    if (cp == NULL ||
	find_path(cp, &editor_path, NULL, getenv("PATH"), 0) != FOUND) {
	sudo_efree(editor);
	debug_return_str(NULL);
    }
    nargv = (char **) sudo_emallocarray(nargc + 1 + nfiles + 1, sizeof(char *));
    for (ac = 0; cp != NULL && ac < nargc; ac++) {
	nargv[ac] = cp;
	cp = strtok(NULL, " \t");
    }
    nargv[ac++] = "--";
    for (i = 0; i < nfiles; )
	nargv[ac++] = files[i++];
    nargv[ac] = NULL;

    *argc_out = nargc;
    *argv_out = nargv;
    debug_return_str(editor_path);
}