s_instr *parse_rule_if(s_lexer *lex)
{
s_list_instr *list_cond = NULL;
s_list_instr *list_instr_t = NULL;
s_instr *instr_f = NULL;
s_token *tok;
if ((NULL == (tok = lexer_pop_token(lex))) ||
(strcmp(tok->str, "if")))
return (NULL);
if (NULL == (list_cond = parse_compound_list(lex)))
return (NULL);
if ((NULL == (tok = lexer_pop_token(lex))) ||
(strcmp(tok->str, "then")))
FREE_LIST_RETURN(list_cond, NULL, NULL);
if ((NULL == (list_instr_t = parse_compound_list(lex))))
FREE_LIST_RETURN(list_cond, NULL, NULL);
if ((NULL == (instr_f = parse_else_clause(lex))) &&
(errno != ENOTFOUND))
FREE_LIST_RETURN(list_cond, list_instr_t, NULL);
if ((NULL == (tok = lexer_pop_token(lex))) ||
(strcmp(tok->str, "fi")))
FREE_LIST_RETURN(list_cond, list_instr_t, instr_f);
return (build_instr(AST_INSTR_IF,
build_instr_if(list_cond, list_instr_t, instr_f)));
}
/* 3.9.4.1 parse a grouping compound
*
* The format for grouping commands is a s follows:
*
* (compound-list) Execute compound-list in a subshell environment;
* Variable assignments and built-in commands that
* affect the environment shall not remain in effect
* after the list finishes.
*
* { compound-list;} Execute compound-list in the current process
* environment.
*
* ----------------------------------------------------------------------- */
union node *parse_grouping(struct parser *p) {
enum tok_flag tok;
union node **rptr;
union node *grouping;
union node *compound_list;
/* return NULL on empty compound */
grouping = NULL;
if(!(tok = parse_expect(p, P_DEFAULT, T_BEGIN|T_LP, NULL)))
return NULL;
/* parse compound content and create a
compound node if there are commands */
if((compound_list = parse_compound_list(p))) {
grouping = tree_newnode(tok == T_BEGIN ? N_CMDLIST : N_SUBSHELL);
grouping->ngrp.cmds = compound_list;
}
/* expect the appropriate ending token */
if(!parse_expect(p, P_DEFAULT, tok << 1, grouping))
return NULL;
if(grouping) {
tree_init(grouping->ngrp.rdir, rptr);
/* now any redirections may follow */
while(parse_gettok(p, P_DEFAULT) & T_REDIR)
tree_move(p->tree, rptr);
p->pushback++;
}
return grouping;
}
s_instr *parse_rule_until(s_lexer *lex)
{
s_list_instr *list_cond = NULL;
s_list_instr *list_instr = NULL;
s_token *tok;
if ((NULL == (tok = lexer_pop_token(lex))) ||
(strcmp(tok->str, "until")))
return (NULL);
if (NULL == (list_cond = parse_compound_list(lex)))
return (NULL);
if (NULL == (list_instr = parse_do_group(lex)))
FREE_LIST_RETURN(list_cond);
return (build_instr(AST_INSTR_UNTIL,
build_instr_until(list_cond, list_instr)));
}
