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#include <stdlib.h>
#include <stdio.h>
#include "lex.h"
#include "parse.h"
Connector parse_connector(Token* toks, size_t* tok_pos) {
Token tok = toks[*tok_pos];
if (tok.kind != TOK_SPECIAL) exit(67);
switch (tok.as.spec) {
case PIPE:
(*tok_pos)++;
return CONN_PIPE;
case EOL:
(*tok_pos)++;
return CONN_EOL;
default: exit(76);
}
}
Command parse_command(Token* toks, size_t* tok_pos) {
TokenVec args = make_TokenVec(256);
RedirectVec redirects = make_RedirectVec(256);
while (true) {
Token curr_tok = toks[*tok_pos];
if (curr_tok.kind == TOK_SPECIAL &&(curr_tok.as.spec == PIPE || curr_tok.as.spec == EOL)) {
break;
}
switch (curr_tok.kind) {
case TOK_SPECIAL:
(*tok_pos)++;
Token name_tok = toks[*tok_pos];
switch (curr_tok.as.spec) {
case WRITE_REDIR_TRUNC:
if(name_tok.kind != TOK_WORD) exit(1);
push_to_RedirectVec(&redirects, (Redirect){.kind = STDOUT_REDIR_TRUNC, .as.std_redir_filename = name_tok.as.word});
break;
case WRITE_REDIR_APPEND:
if(name_tok.kind != TOK_WORD) exit(1);
push_to_RedirectVec(&redirects, (Redirect){.kind = STDOUT_REDIR_APPEND, .as.std_redir_filename = name_tok.as.word});
break;
case READ_REDIR:
if(name_tok.kind != TOK_WORD) exit(1);
push_to_RedirectVec(&redirects, (Redirect){.kind = STDOUT_REDIR_APPEND, .as.std_redir_filename = name_tok.as.word});
break;
default:
exit(69);
}
break;
default:
push_to_TokenVec(&args, curr_tok);
}
(*tok_pos)++;
}
return (Command){.args = args, .redirects = redirects};
}
Pipeline parse_tokstream(Token* toks) {
size_t tok_pos = 0;
Pipeline result = make_Pipeline(256);
while (true) {
Command cmd = parse_command(toks, &tok_pos);
Connector conn = parse_connector(toks, &tok_pos);
push_to_Pipeline(&result, (PipelineElement){.cmd = cmd, .conn = conn});
if (conn == CONN_EOL) break;
}
return result;
}
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