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#include "lexical_analysis.h"
#include <stdio.h>
int is_double_quotes_pair(struct param_type params)
{
return !(params.double_quotes_counter % 2);
}
int escape_double_quotes_or_backslash(int ch, struct param_type params)
{
return params.escape_sequences &&
(ch == double_quotes || ch == backslash);
}
int double_quotes_again(int ch, struct param_type params)
{
return ch == double_quotes && !params.is_word &&
params.stored_symbol == '"';
}
int check_separation(int ch, struct param_type params)
{
return (ch == whitespace || ch == tab) && params.is_word &&
!params.escape_sequences;
}
int ignore_spaces(int ch, struct param_type params)
{
return (ch == whitespace || ch == tab) && !params.escape_sequences;
}
int change_mode(int ch, struct param_type params)
{
return ch == '"' && !params.escape_sequences;
}
int start_escape_sequence(int ch, struct param_type params)
{
return ch == backslash && !params.escape_sequences;
}
int is_empty_word(int ch, struct param_type params)
{
return (ch == whitespace || ch == tab) && !params.is_word &&
params.empty_word_flag;
}
static int find_end_subshell_before_cur_pos(struct readline_type *readline)
{
int i;
for(i = readline->considered_index-1; i >= 0; --i) {
if(readline->arr[i] == ' ')
continue;
break;
}
return i >= 0 && readline->arr[i] == ')';
}
int command_execution_condition(struct param_type *params,
struct readline_type *readline)
{
if(params->tokens == and || params->tokens == or) {
if(find_end_subshell_before_cur_pos(readline))
return 0;
}
if(params->tokens == next_command) {
if(find_end_subshell_before_cur_pos(readline))
return 0;
}
if(params->tokens == '&') {
if(find_end_subshell_before_cur_pos(readline))
return 0;
}
if(params->tokens == '(' && params->pipeline)
return 1;
return
(params->tokens != '<' && params->tokens != '>' &&
params->tokens != append && !params->pipeline &&
params->tokens != start_subshell) ||
(params->pipeline && params->tokens == '&');
}
int is_first_special_token_character(int ch)
{
return ch == '<' || ch == '>' || ch == '&' || ch == '|' || ch == ';';
}
int excessive_words(int ch, struct param_type *params,
struct readline_type *readline)
{
if(filename_waiting(params)) {
if(ch == new_line)
return 0;
int i;
for(i = readline->considered_index+1; i <= readline->last_element_index;
++i)
{
if(readline->arr[i] == ' ')
continue;
if(!is_first_special_token_character(readline->arr[i])) {
params->wrong_command = err_extra_chars_after_filename;
return 1;
} else
break;
}
}
return 0;
}
void add_word_or_filename(struct w_queue *word_chain,
struct dynamic_array *tmp_word,
struct param_type *params)
{
/* filenames */
if(filename_waiting(params) && !params->wrong_command)
add_filename(tmp_word, params);
/* execute command */
else if(params->is_word)
add_word(word_chain, tmp_word, params);
}
int validate_redirections(int ch, int next_ch, struct param_type *params)
{
return (ch == '<' && params->streams.input_stream == NULL) ||
((ch == '>' || (ch == '>' && next_ch == '>')) &&
params->streams.output_stream == NULL &&
params->streams.output_stream_to_append == NULL);
}
int is_special_token(int ch, int next_ch)
{
return (ch == '&' && next_ch == '&') || (ch == '|' && next_ch == '|') ||
ch == '&' || ch == ';' || ch == '|' || ch == '(' || ch == ')';
}
int is_redirect_token(int ch, int next_ch)
{
return ch == '<' || ch == '>' || (ch == '>' && next_ch == '>');
}
/*
* redirection token verification
*/
int stream_redirect_tokens(struct w_queue *word_chain,
struct dynamic_array *tmp_word, int ch,
struct param_type *params,
struct readline_type *readline)
{
int next_ch;
if(ch == '>')
next_ch = readline->arr[readline->considered_index + 1];
if(is_redirect_token(ch, next_ch)) {
add_word_or_filename(word_chain, tmp_word, params);
if(params->wrong_command)
return 0;
if(validate_redirections(ch, next_ch, params)) {
params->tokens = (ch == '>' && next_ch == '>') ? append : ch;
if(params->tokens == append)
readline->considered_index += 2;
return 1;
} else
params->wrong_command = err_redirect_stream_again;
}
return 0;
}
/*
* the first element of the pipeline outputs to a file or
* redirects to a file in the middle of the pipeline
*/
int wrong_streams_redirection(struct param_type *params)
{
return
(!params->pipeline && (params->tokens == '>' ||
params->tokens == append)) ||
(params->pipeline && (params->tokens == '>' ||
params->tokens == append ||
params->tokens == '<'));
}
int pipeline_token_processing(struct w_queue *word_chain,
struct c_queue *cmdlines,
struct dynamic_array *tmp_word,
struct param_type *params)
{
/* pipeline after subshell */
if(tmp_word->last_element_index == -1 && params->tokens == start_subshell) {
params->tokens = '|';
params->pipeline = 1;
return 1;
}
char **cmdline = NULL;
if(is_stream_redirection_set(params) &&
wrong_streams_redirection(params)) {
params->wrong_command = err_redirect_stream_in_pipeline;
return 0;
}
params->tokens = '|';
params->pipeline = 1;
cmdline =
create_cmdline(word_chain, w_queue_get_word_count(word_chain));
c_queue_push(cmdlines, cmdline);
w_queue_clear(word_chain);
dynarr_reset_array(tmp_word);
return 1;
}
static void stop_by_previous_effect_tokens(struct param_type *params)
{
if((params->tokens == and && last_execution_status == 1) ||
(params->tokens == or && last_execution_status == 0))
params->wrong_command = err_set_failure;
}
static int find_repeated_background_symbol(struct readline_type *readline)
{
int i;
for(i = readline->considered_index + 1; i <= readline->last_element_index;
++i)
{
if(readline->arr[i] == '&')
return 1;
}
return 0;
}
/*
* verification of special tokens (|, &, &&, ||), except redirection tokens
*/
int special_tokens(struct w_queue *word_chain, struct c_queue *cmdlines,
struct dynamic_array *tmp_word, int *ch,
struct param_type *params, struct readline_type *readline)
{
int next_ch, i;
if(*ch == '|' || *ch == '&')
next_ch = readline->arr[readline->considered_index + 1];
if(is_special_token(*ch, next_ch)) {
add_word_or_filename(word_chain, tmp_word, params);
stop_by_previous_effect_tokens(params);
if(params->wrong_command)
return 0;
if(*ch == '|' && next_ch == '|') {
params->tokens = or;
readline->considered_index += 2;
return 1;
}
if(*ch == '|')
return pipeline_token_processing(word_chain, cmdlines, tmp_word,
params);
if(*ch == '&' && next_ch == '&') {
params->tokens = and;
readline->considered_index += 2;
return 1;
}
if(*ch == '&') {
/* repeated & */
if(find_repeated_background_symbol(readline)) {
params->wrong_command = err_repeated_background_ch;
return 0;
}
for(i = readline->considered_index+1; readline->arr[i] != new_line;
++i) {
if(readline->arr[i] == ' ')
continue;
else
break;
}
if(readline->arr[i] == new_line)
*ch = new_line;
params->tokens = '&';
return 1;
}
if(*ch == start_subshell) {
params->tokens = start_subshell;
return 1;
}
if(*ch == end_subshell) {
params->tokens = end_subshell;
return 1;
}
if(*ch == next_command) {
params->tokens = next_command;
return 1;
}
return 1;
}
return 0;
}
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