Initial commit: psh - minimal bash-like shell with && || operators and tab completion

Makefile

@@ -0,0 +1,27 @@
+CC = gcc
+CFLAGS = -Wall -Wextra -std=c99 -O2
+LDFLAGS =
+
+TARGET = psh.exe
+SRC = psh.c
+
+.PHONY: all clean test
+
+all: $(TARGET)
+
+$(TARGET): $(SRC)
+	$(CC) $(CFLAGS) -o $@ $< $(LDFLAGS)
+
+test: $(TARGET)
+	@echo "Testing psh..."
+	./$(TARGET) -c "echo hello"
+	./$(TARGET) -c "pwd"
+	./$(TARGET) -c "dir | findstr .exe"
+	@echo "Tests passed!"
+
+clean:
+	rm -f $(TARGET) *.o
+
+# Build with readline support (if available)
+readline: $(SRC)
+	$(CC) $(CFLAGS) -DHAVE_READLINE -lreadline -o $(TARGET) $(SRC)

README.md

@@ -0,0 +1,115 @@
+# psh - A minimal bash-like shell in pure C
+
+A lightweight POSIX shell implementation featuring:
+
+- Command execution via fork/exec (Windows: CreateProcess)
+- Built-in commands: `cd`, `pwd`, `echo`, `exit`, `help`, `env`
+- Input/output redirection (`<`, `>`, `>>`)
+- Piping (`|`)
+- Background execution (`&`)
+- Command history with up/down arrows
+- Tab completion
+- `&&` and `||` operators
+- Basic environment variable support
+- Tilde expansion (`~`)
+
+## Building
+
+```bash
+make
+```
+
+Requires:
+- GCC or compatible C compiler
+- GNU Readline library (for line editing)
+
+## Running
+
+```bash
+./psh
+```
+
+## Features
+
+### Built-ins
+- `cd [dir]` - Change directory
+- `pwd` - Print working directory
+- `echo [args]` - Print text (supports `$VAR` expansion)
+- `exit` - Exit shell
+- `help` - Show help
+- `env [var=val]` - Show or set environment variables
+- `history` - Show command history
+
+### Redirection
+```bash
+ls > output.txt      # Redirect output
+cat < input.txt      # Redirect input
+echo hi >> log.txt   # Append output
+```
+
+### Piping
+```bash
+ps aux | grep python | wc -l
+```
+
+### Background
+```bash
+sleep 100 &
+```
+
+### Logical Operators
+```bash
+cmd1 && cmd2    # Execute cmd2 only if cmd1 succeeds
+cmd1 || cmd2    # Execute cmd2 only if cmd1 fails
+```
+
+### Tab Completion
+Press `Tab` to complete commands:
+- Built-in commands (cd, pwd, echo, etc.)
+- Executable files in PATH and current directory
+- Environment variables
+
+### Command History
+- ↑/↓ arrows: Navigate history
+- Tab: Try completion
+- Backspace: Delete character
+
+## Example Session
+
+```
+user@localhost:F:\Paze SH> echo Hello World
+Hello World
+
+user@localhost:F:\Paze SH> ls && echo "List completed"
+psh.c  README.md  Makefile
+List completed
+
+user@localhost:F:\Paze SH> false || echo "Fallback executed"
+Fallback executed
+
+user@localhost:F:\Paze SH> help
+psh - minimal bash-like shell (Windows)
+
+Built-in commands:
+  cd [dir]     Change directory
+  pwd          Print working directory
+  echo [args]  Print arguments
+  exit         Exit shell
+  env [var=val] Show/set environment
+  help         Show this help
+
+Features:
+  cmd1 | cmd2       Pipe output
+  cmd > file        Redirect output
+  cmd >> file       Append output
+  cmd < file        Redirect input
+  cmd &             Run in background
+  cmd1 && cmd2      Execute cmd2 if cmd1 succeeds
+  cmd1 || cmd2      Execute cmd2 if cmd1 fails
+  history           View command history
+  Tab               Try command completion
+```
+
+## License
+
+MIT

test.c

@@ -0,0 +1,84 @@
+/*
+ * psh - Test cases for the shell
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <windows.h>
+
+/* Test helper */
+int run_test(const char *cmd, const char *expected_substring) {
+    char output[4096];
+    FILE *fp;
+    int passed = 0;
+
+    printf("Testing: %s\n", cmd);
+
+    /* Run command and capture output */
+    char full_cmd[4096];
+    snprintf(full_cmd, sizeof(full_cmd), "psh.exe -c \"%s\" 2>&1", cmd);
+
+    fp = _popen(full_cmd, "r");
+    if (fp == NULL) {
+        printf("  FAILED: Could not execute command\n");
+        return 0;
+    }
+
+    memset(output, 0, sizeof(output));
+    if (fread(output, 1, sizeof(output) - 1, fp) > 0) {
+        /* Remove trailing newline */
+        output[strcspn(output, "\n")] = '\0';
+
+        if (strstr(output, expected_substring) != NULL) {
+            printf("  PASSED: Got expected output containing '%s'\n", expected_substring);
+            passed = 1;
+        } else {
+            printf("  FAILED: Expected output containing '%s', got: '%s'\n", expected_substring, output);
+        }
+    } else {
+        printf("  FAILED: No output from command\n");
+    }
+
+    _pclose(fp);
+    return passed;
+}
+
+int main() {
+    int passed = 0;
+    int total = 0;
+
+    printf("=== psh Test Suite ===\n\n");
+
+    /* Test 1: echo */
+    total++;
+    if (run_test("echo hello", "hello")) passed++;
+
+    /* Test 2: pwd */
+    total++;
+    if (run_test("pwd", "F:\\Paze SH")) passed++;
+
+    /* Test 3: environment variables */
+    total++;
+    if (run_test("echo $HOME", "")) passed++;  /* Just check it doesn't crash */
+
+    /* Test 4: help */
+    total++;
+    if (run_test("help", "Built-in commands")) passed++;
+
+    /* Test 5: history (empty) */
+    total++;
+    if (run_test("history", "history")) passed++;
+
+    /* Test 6: && operator */
+    total++;
+    if (run_test("echo first && echo second", "first")) passed++;
+
+    /* Test 7: || operator */
+    total++;
+    if (run_test("false || echo fallback", "fallback")) passed++;
+
+    printf("\n=== Results: %d/%d tests passed ===\n", passed, total);
+
+    return (passed == total) ? 0 : 1;
+}

test_input.txt

@@ -0,0 +1,8 @@
+test1: echo Hello World
+test2: pwd
+test3: ls | findstr .exe
+test4: echo $HOME
+test5: mkdir testdir && cd testdir && pwd
+test6: false || echo "This should print"
+test7: true && echo "This should also print"
+test8: env