42_minishell/src/parse_command.c
2024-04-29 15:49:12 +02:00

145 lines
4.1 KiB
C

/* ************************************************************************** */
/* */
/* ::: :::::::: */
/* parse_command.c :+: :+: :+: */
/* +:+ +:+ +:+ */
/* By: mcolonna <marvin@42.fr> +#+ +:+ +#+ */
/* +#+#+#+#+#+ +#+ */
/* Created: 2024/04/24 13:47:40 by mcolonna #+# #+# */
/* Updated: 2024/04/29 15:48:43 by mcolonna ### ########.fr */
/* */
/* ************************************************************************** */
#include "include.h"
// To call when a parse error occurs.
// Always returns 1 (parse error's status).
static int parse_error(void)
{
minishell_error("parse error");
return (1);
}
// Global variables for all the parsing functions
typedef struct s_parsing_args
{
t_memclass mc;
t_command r;
t_stream stream;
t_list calls;
bool got_first_call; // got at least the first program call?
} t_parsing_args;
// Skip blank characters
static void skip_blank(t_stream *stream)
{
stream_skip(stream, " \r\n\t");
}
// Read the string, stop if the char is in stop_charset
// TODO quotes
static const char *get_string(t_parsing_args *args, const char *stop_charset)
{
const t_memclass mc = mem_subclass(fatal_error, args->mc);
const char *stop_charset_2
= str_join(fatal_error, mc, stop_charset, " \n");
char *str;
char str2[2];
char *str3;
str = str_dup(fatal_error, mc, "");
str2[1] = '\0';
while (stream_read(&args->stream)
&& !char_isin(stream_read(&args->stream), stop_charset_2))
{
str2[0] = stream_pop(&args->stream);
str3 = str;
str = str_join(fatal_error, mc, str, str2);
mem_free(str3);
}
str = str_dup(fatal_error, args->mc, str);
mem_freeall(mc);
return (str);
}
// Get a program call (program names & its arguments) until stop_charset.
static int get_call(t_parsing_args *args, const char *stop_charset)
{
t_call *r;
t_list arguments;
arguments = list_createempty(args->mc);
while (stream_read(&args->stream)
&& !char_isin(stream_read(&args->stream), stop_charset))
{
list_add(fatal_error, &arguments,
(char *)get_string(args, stop_charset));
skip_blank(&args->stream);
}
r = mem_alloc(fatal_error, args->mc, sizeof(t_call));
r->program = (char *)list_get(err_remember, &arguments, 0);
if (err_get())
return (parse_error());
r->argc = list_getsize(&arguments);
r->argv = (char *const *)list_convert(
fatal_error, args->mc, &arguments);
list_add(fatal_error, &args->calls, (t_call *)r);
args->got_first_call = true;
return (0);
}
// Read an element (a call to a program, a '< FILE' or a '> FILE')
// On success, return 0. On error, return the error status.
// (TODO redirections)
static int get_element(t_parsing_args *args)
{
char c;
int error;
error = 0;
while (!error && stream_read(&args->stream))
{
c = stream_read(&args->stream);
if (c == '|')
{
if (!args->got_first_call)
return (parse_error());
stream_pop(&args->stream);
skip_blank(&args->stream);
error = get_call(args, "<>|");
}
else if (!args->got_first_call)
error = get_call(args, "<>|");
else
return (parse_error());
skip_blank(&args->stream);
}
return (error);
}
t_command parse_command(const t_memclass mc, const char *command)
{
t_parsing_args args;
int error;
error = 0;
args.mc = mc;
args.r.error = 0;
args.r.input_fd = 0;
args.r.output_fd = 1;
args.calls = list_createempty(mc);
args.got_first_call = false;
streamstr_init(&args.stream, command);
skip_blank(&args.stream);
while (!error && stream_read(&args.stream))
{
error = get_element(&args);
skip_blank(&args.stream);
}
if (!error)
args.r.calls = (t_call *)list_convert_type(
fatal_error, args.mc, &args.calls, sizeof(t_call));
if (error)
args.r.error = error;
return (args.r);
}