int main()
{
cmd_list *list;
parser_info pinfo;
init_parser(&pinfo);
do {
list = parse_cmd_list(&pinfo);
switch (pinfo.error) {
case 0:
print_cmd_list(stdout, list, 1);
destroy_cmd_list(list);
list = NULL;
break;
case 16:
fprintf(stderr, "Parser: empty command;\n");
break;
default:
/* TODO: flush read buffer,
* possibly via buffer function. */
fprintf(stderr, "Parser: bad command;\n");
break;
}
if (pinfo.cur_lex->type == LEX_EOFILE)
exit(pinfo.error);
} while (1);
return 0;
}
void destroy_cmd_pipeline(cmd_pipeline *pipeline)
{
cmd_pipeline_item *current;
cmd_pipeline_item *next;
if (pipeline == NULL)
return;
current = pipeline->first_item;
while (current != NULL) {
next = current->next;
destroy_argv(current->argv);
destroy_cmd_list(current->cmd_lst);
free(current);
current = next;
}
if (pipeline->input != NULL)
free(pipeline->input);
if (pipeline->output != NULL)
free(pipeline->output);
free(pipeline);
}
cmd_list *parse_cmd_list(parser_info *pinfo)
{
int bracket_terminated = 0;
int lex_term = 0;
cmd_list *list = make_cmd_list(pinfo);
cmd_list_item *cur_item = NULL, *tmp_item = NULL;
#ifdef PARSER_DEBUG
parser_print_action(pinfo, "parse_cmd_list()", 0);
#endif
if (pinfo->cur_lex != NULL)
bracket_terminated = (pinfo->cur_lex->type == LEX_BRACKET_OPEN);
parser_get_lex(pinfo);
if (pinfo->error)
goto error;
switch (pinfo->cur_lex->type) {
case LEX_EOLINE:
case LEX_EOFILE:
/* Empty cmd list */
pinfo->error = 16; /* Error 16 */
goto error;
default:
/* Do nothing */
break;
}
do {
tmp_item = parse_cmd_list_item(pinfo);
if (pinfo->error)
goto error;
if (list->first_item == NULL)
list->first_item = cur_item = tmp_item;
else
cur_item = cur_item->next = tmp_item;
switch (pinfo->cur_lex->type) {
case LEX_BACKGROUND:
case LEX_BRACKET_CLOSE:
case LEX_EOLINE:
case LEX_EOFILE:
lex_term = 1;
break;
default:
pinfo->error = (cur_item->rel == REL_NONE) ? 15 : 0; /* Error 15 */
break;
}
} while (!lex_term && !pinfo->error);
if (pinfo->error)
goto error;
if (pinfo->cur_lex->type == LEX_BACKGROUND) {
pinfo->error = (cur_item->rel == REL_NONE) ? 0 : 13; /* Error 13 */
if (pinfo->error)
goto error;
list->foreground = 0;
parser_get_lex(pinfo);
}
if (pinfo->error)
goto error;
switch (pinfo->cur_lex->type) {
case LEX_BRACKET_CLOSE:
pinfo->error = (bracket_terminated) ? 0 : 5; /* Error 5 */
break;
case LEX_EOLINE:
case LEX_EOFILE:
pinfo->error = (bracket_terminated) ? 6 : 0; /* Error 6 */
break;
default:
pinfo->error = 14; /* Error 14 */
break;
}
if (pinfo->error)
goto error;
pinfo->error = ((cur_item->rel == REL_NONE)
|| (cur_item->rel == REL_BOTH)) ? 0 : 7; /* Error 7 */
if (pinfo->error)
goto error;
cur_item->rel = REL_NONE;
#ifdef PARSER_DEBUG
parser_print_action(pinfo, "parse_cmd_list()", 1);
#endif
return list;
error:
#ifdef PARSER_DEBUG
parser_print_error(pinfo, "parse_cmd_list()");
#endif
destroy_cmd_list(list);
return NULL;
}
int evaluate(struct SLList *tokens) {
struct SLList cmds;
init_list(&cmds);
IOModifier prev_mod = NO_MODIFIER;
struct ExecutableCmd *exe = (struct ExecutableCmd *)malloc(sizeof(struct ExecutableCmd));
init_executable_cmd(exe);
while (tokens->length != 0) {
struct Token *tok = pop_front(tokens);
// check for output redirection conflicts here.
if ( prev_mod == PIPE ) {
if (exe->output_redir_to) { // conflict
// dump the token and cmd lists.
destroy_token(tok);
while ( (tok = pop_front(tokens)) ) destroy_token(tok);
destroy_exe_cmd(exe);
destroy_cmd_list(&cmds);
fprintf(stderr, "error: syntax error in output redirection.\n");
return -1;
}
add_back(&cmds, exe);
exe = (struct ExecutableCmd *)malloc(sizeof(struct ExecutableCmd));
init_executable_cmd(exe);
prev_mod = NO_MODIFIER;
}
// use previous token's mod, if mod exists,
// and this token's info to populate redirection of exe.
if (prev_mod == INPUT_REDIR) {
exe->input_redir_from = make_file_path(tok->name);
} else if (prev_mod == OUTPUT_REDIR) {
exe->output_redir_to = make_file_path(tok->name);
} else if (prev_mod == ERR_OUTPUT_REDIR) {
exe->err_output_redir_to = make_file_path(tok->name);
}
if ( prev_mod == NO_MODIFIER ) {
if ( (exe->full_path = find_cmd(tok->name)) != NULL ) {
exe->args = populate_args(tok);
if (tok->mod == NO_MODIFIER) {
add_back(&cmds, exe);
}
} else {
fprintf(stderr, "error: not a valid command.\n");
destroy_token(tok);
destroy_exe_cmd(exe);
destroy_cmd_list(&cmds);
return -1;
}
} else if (tok->mod == NO_MODIFIER) {
add_back(&cmds, exe);
}
prev_mod = tok->mod;
destroy_token(tok);
}
// Execute the commands.
int exe_status = execute_cmds(&cmds);
// TODO: destroy the cmds list.
destroy_cmd_list(&cmds);
// return 0 if everything went peachy.
return exe_status;
}
