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#include <stdlib.h>
#include <stdio.h>
#include "lex.h"
#include "parse.h"
typedef struct {
TokenVec vec;
size_t pos;
} TokStream;
Connector parse_connector(TokStream* toks) {
Token tok = *get_from_TokenVec(&toks->vec, toks->pos);
if (tok.kind != TOK_SPECIAL) exit(67);
switch (tok.as.spec) {
case PIPE:
toks->pos++;
return CONN_PIPE;
case EOL:
toks->pos++;
return CONN_EOL;
default: exit(76);
}
}
Command parse_command(TokStream* toks) {
TokenVec args = make_TokenVec(256);
RedirectVec redirects = make_RedirectVec(256);
while (true) {
Token curr_tok = *get_from_TokenVec(&toks->vec, toks->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:
toks->pos++;
Token name_tok = *get_from_TokenVec(&toks->vec, toks->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);
}
toks->pos++;
}
return (Command){.args = args, .redirects = redirects};
}
Pipeline parse_tokstream(TokenVec tok_vec) {
TokStream tokstream = {.vec = tok_vec, .pos = 0};
Pipeline result = make_Pipeline(256);
while (true) {
Command cmd = parse_command(&tokstream);
Connector conn = parse_connector(&tokstream);
push_to_Pipeline(&result, (PipelineElement){.cmd = cmd, .conn = conn});
if (conn == CONN_EOL) break;
}
return result;
}
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