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Userspace: Shell now processes $ arguments

This commit is contained in:
Bananymous 2023-06-19 01:39:24 +03:00
parent 46a6daccfe
commit 84ecf861cd
1 changed files with 81 additions and 3 deletions
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84
userspace/Shell/main.cpp
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@ -1,6 +1,8 @@
#include <BAN/Optional.h>
#include <BAN/ScopeGuard.h>
#include <BAN/String.h>
#include <BAN/Vector.h>
#include <ctype.h>
#include <stdio.h>
#include <stdlib.h>
@ -10,6 +12,59 @@
struct termios old_termios, new_termios;
BAN::Optional<BAN::String> parse_dollar(BAN::StringView command, size_t& i)
{
ASSERT(command[i] == '$');
if (++i >= command.size())
return "$"sv;
if (isalnum(command[i]))
{
size_t len = 1;
for (; i + len < command.size(); len++)
if (!isalnum(command[i + len]))
break;
BAN::String name = command.substring(i, len);
i += len - 1;
if (const char* value = getenv(name.data()))
return BAN::StringView(value);
return ""sv;
}
else if (command[i] == '{')
{
size_t len = 1;
for (; i + len < command.size(); len++)
{
if (command[i + len] == '}')
break;
if (!isalnum(command[i + len]))
return {};
}
if (i + len >= command.size())
return {};
BAN::String name = command.substring(i + 1, len - 1);
i += len;
if (const char* value = getenv(name.data()))
return BAN::StringView(value);
return ""sv;
}
else if (command[i] == '[')
{
return {};
}
else if (command[i] == '(')
{
return {};
}
return "$"sv;
}
BAN::Vector<BAN::String> parse_command(BAN::StringView command)
{
enum class State
@ -23,8 +78,10 @@ BAN::Vector<BAN::String> parse_command(BAN::StringView command)
State state = State::Normal;
BAN::String current;
for (char c : command)
for (size_t i = 0; i < command.size(); i++)
{
char c = command[i];
switch (state)
{
case State::Normal:
@ -32,6 +89,16 @@ BAN::Vector<BAN::String> parse_command(BAN::StringView command)
state = State::SingleQuote;
else if (c == '"')
state = State::DoubleQuote;
else if (c == '$')
{
auto expansion = parse_dollar(command, i);
if (!expansion.has_value())
{
fprintf(stderr, "bad substitution\n");
return {};
}
MUST(current.append(expansion.value()));
}
else if (!isspace(c))
MUST(current.push_back(c));
else
@ -52,8 +119,18 @@ BAN::Vector<BAN::String> parse_command(BAN::StringView command)
case State::DoubleQuote:
if (c == '"')
state = State::Normal;
else
else if (c != '$')
MUST(current.push_back(c));
else
{
auto expansion = parse_dollar(command, i);
if (!expansion.has_value())
{
fprintf(stderr, "bad substitution\n");
return {};
}
MUST(current.append(expansion.value()));
}
break;
}
}
@ -181,7 +258,7 @@ BAN::String get_prompt()
{
const char* raw_prompt = getenv("PS1");
if (raw_prompt == nullptr)
raw_prompt = "\e[32muser@host\e[m:\e[34m\\~\e[m$ ";
return ""sv;
BAN::String prompt;
for (int i = 0; raw_prompt[i]; i++)
@ -254,6 +331,7 @@ int main(int argc, char** argv)
{
if (argc >= 1)
setenv("SHELL", argv[0], true);
setenv("PS1", "\e[32muser@host\e[m:\e[34m\\~\e[m$ ", false);
tcgetattr(0, &old_termios);