userspace: add sh program

Signed-off-by: EnderIce2 <enderice2@protonmail.com>

Userspace/apps/sys/sh/Makefile

@@ -0,0 +1,33 @@
+default:
+	$(error Do not run this Makefile directly!)
+
+S_SOURCES = $(shell find ./ -type f -name '*.S')
+C_SOURCES = $(shell find ./ -type f -name '*.c')
+CXX_SOURCES = $(shell find ./ -type f -name '*.cpp')
+
+OBJ = $(S_SOURCES:.S=.o) $(C_SOURCES:.c=.o) $(CXX_SOURCES:.cpp=.o)
+
+FILENAME = $(notdir $(shell pwd))
+WARNCFLAG = -Wall -Wextra
+
+build: $(FILENAME).elf
+	cp $(FILENAME).elf $(WORKSPACE_DIR)/out/bin/$(FILENAME)
+
+$(FILENAME).elf: $(OBJ)
+	$(info Linking $@)
+	$(CC) $(LDFLAGS) $(SYSROOT) $(OBJ) -o $@
+
+%.o: %.c $(HEADERS)
+	$(info Compiling $<)
+	$(CC) $(CFLAGS) $(WARNCFLAG) -std=c17 -c $< -o $@
+
+%.o: %.cpp $(HEADERS)
+	$(info Compiling $<)
+	$(CXX) $(CFLAGS) $(WARNCFLAG) -std=c++20 -fexceptions -c $< -o $@ -fno-rtti
+
+%.o: %.S
+	$(info Compiling $<)
+	$(AS) -o $@ $<
+
+clean:
+	rm -f $(OBJ) $(FILENAME).elf

Userspace/apps/sys/sh/sh.c

@@ -0,0 +1,114 @@
+/*
+	This file is part of Fennix Userspace.
+
+	Fennix Userspace is free software: you can redistribute it and/or
+	modify it under the terms of the GNU General Public License as
+	published by the Free Software Foundation, either version 3 of
+	the License, or (at your option) any later version.
+
+	Fennix Userspace is distributed in the hope that it will be useful,
+	but WITHOUT ANY WARRANTY; without even the implied warranty of
+	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+	GNU General Public License for more details.
+
+	You should have received a copy of the GNU General Public License
+	along with Fennix Userspace. If not, see <https://www.gnu.org/licenses/>.
+*/
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <sys/wait.h>
+#include <signal.h>
+
+#define MAX_INPUT_SIZE 1024
+#define MAX_ARG_SIZE 100
+
+void print_prompt()
+{
+	printf("$ ");
+	fflush(stdout);
+}
+
+void read_input(char *input)
+{
+	if (fgets(input, MAX_INPUT_SIZE, stdin) == NULL)
+	{
+		perror("fgets");
+		exit(EXIT_FAILURE);
+	}
+	input[strcspn(input, "\n")] = '\0';
+}
+
+void parse_input(char *input, char **args)
+{
+	int i = 0;
+	args[i] = strtok(input, " ");
+	while (args[i] != NULL)
+	{
+		i++;
+		args[i] = strtok(NULL, " ");
+	}
+}
+
+void execute_command(char **args)
+{
+	pid_t pid = fork();
+	if (pid < 0)
+	{
+		perror("fork");
+		exit(EXIT_FAILURE);
+	}
+	else if (pid == 0)
+	{
+		if (execvp(args[0], args) < 0)
+		{
+			perror("execvp");
+			exit(EXIT_FAILURE);
+		}
+	}
+	else
+	{
+		int status;
+		waitpid(pid, &status, 0);
+		if (WIFEXITED(status))
+		{
+			printf("Child exited with status %d\n", WEXITSTATUS(status));
+		}
+		else if (WIFSIGNALED(status))
+		{
+			printf("Child terminated by signal %d\n", WTERMSIG(status));
+		}
+	}
+}
+
+void handle_signal(int sig)
+{
+	if (sig == SIGINT)
+	{
+		printf("\nCaught signal %d (SIGINT). Type 'exit' to quit the shell.\n", sig);
+		print_prompt();
+		fflush(stdout);
+	}
+}
+
+int main()
+{
+	char input[MAX_INPUT_SIZE];
+	char *args[MAX_ARG_SIZE];
+
+	signal(SIGINT, handle_signal);
+
+	while (1)
+	{
+		print_prompt();
+		read_input(input);
+		if (strcmp(input, "exit") == 0)
+			break;
+		parse_input(input, args);
+		if (args[0] != NULL)
+			execute_command(args);
+	}
+
+	return 0;
+}