London | 26-SDC-Mar | Ebrahim Beiati-Asl | Sprint 4 | Implement shell python shell tools

implement-shell-tools/implement-shell-tools-python/cat/cat.py

@@ -0,0 +1,61 @@
+#!/usr/bin/env python3
+import sys
+import os
+
+global_line_counter = 1
+
+def print_file(file_path, options):
+    global global_line_counter
+    try:
+        with open(file_path, "r", encoding="utf-8") as f:
+            content = f.read()
+
+        lines = content.split("\n")
+        if lines and lines[-1] == "":
+            lines.pop()
+
+        for line in lines:
+            prefix = ""
+
+            should_number = (
+                options["number_mode"] == "all" or
+                (options["number_mode"] == "non-empty" and line.strip() != "")
+            )
+
+            if should_number:
+                prefix = f"{global_line_counter:6}\t"
+                global_line_counter += 1
+
+            sys.stdout.write(prefix + line + "\n")
+
+    except Exception as e:
+        print(f"cat: {file_path}: {e}", file=sys.stderr)
+        sys.exit(1)
+
+
+def main():
+    global global_line_counter
+    args = sys.argv[1:]
+
+    options = {"number_mode": "off"}
+    files = []
+
+    for arg in args:
+        if arg == "-n":
+            options["number_mode"] = "all"
+        elif arg == "-b":
+            options["number_mode"] = "non-empty"
+        else:
+            files.append(arg)
+
+    if not files:
+        print("cat: missing file operand", file=sys.stderr)
+        sys.exit(1)
+
+    for file_path in files:
+        global_line_counter = 1
+        print_file(file_path, options)
+
+
+if __name__ == "__main__":
+    main()

implement-shell-tools/implement-shell-tools-python/ls/ls.py

@@ -0,0 +1,47 @@
+#!/usr/bin/env python3
+import sys
+import os
+
+def list_directory(path, show_all, one_per_line):
+    try:
+        entries = os.listdir(path)
+        if show_all:
+            # Add . and .. when -a is used
+            entries = [".", ".."] + entries
+        else:
+            entries = [e for e in entries if not e.startswith(".")]
+
+        entries.sort(key=lambda x: (x not in (".", ".."), x))
+
+        for e in entries:
+            print(e)
+
+    except Exception as e:
+        print(f"Error reading directory {path}: {e}", file=sys.stderr)
+        sys.exit(1)
+
+
+def main():
+    args = sys.argv[1:]
+
+    show_all = "-a" in args
+    one_per_line = "-1" in args
+
+    dirs = [a for a in args if a not in ("-a", "-1")]
+
+    if not dirs:
+        dirs = [os.getcwd()]
+
+    for i, path in enumerate(dirs):
+            if os.path.isdir(path):
+                if len(dirs) > 1:
+                    print(f"{path}:")
+                list_directory(path, show_all, one_per_line)
+                if len(dirs) > 1 and i < len(dirs) - 1:
+                    print("")
+            else:
+                print(path)
+
+
+if __name__ == "__main__":
+    main()

implement-shell-tools/implement-shell-tools-python/wc/wc.py

@@ -0,0 +1,70 @@
+#!/usr/bin/env python3
+import sys
+
+def count_file_content(content):
+    raw_lines = content.split("\n")
+    lines = len(raw_lines) - 1 if raw_lines[-1] == "" else len(raw_lines)
+    words = len(content.split())
+    bytes_ = len(content.encode("utf-8"))
+    return lines, words, bytes_
+
+
+def print_counts(path, counts, options):
+    parts = []
+    if options["line"]:
+        parts.append(str(counts[0]).rjust(8))
+    if options["word"]:
+        parts.append(str(counts[1]).rjust(8))
+    if options["byte"]:
+        parts.append(str(counts[2]).rjust(8))
+
+    output = "".join(parts)
+    print(f"{output} {path}")
+
+
+def main():
+    args = sys.argv[1:]
+
+    options = {"line": False, "word": False, "byte": False}
+    files = []
+
+    for arg in args:
+        if arg == "-l":
+            options["line"] = True
+        elif arg == "-w":
+            options["word"] = True
+        elif arg == "-c":
+            options["byte"] = True
+        else:
+            files.append(arg)
+
+    if not files:
+        print("No files specified", file=sys.stderr)
+        sys.exit(1)
+
+    if not any(options.values()):
+        options = {"line": True, "word": True, "byte": True}
+
+    total = [0, 0, 0]
+    multiple = len(files) > 1
+
+    for path in files:
+        try:
+            with open(path, "r", encoding="utf-8") as f:
+                content = f.read()
+
+            counts = count_file_content(content)
+            total = [t + c for t, c in zip(total, counts)]
+
+            print_counts(path, counts, options)
+
+        except Exception as e:
+            print(f"Error reading file {path}: {e}", file=sys.stderr)
+            sys.exit(1)
+
+    if multiple:
+        print_counts("total", total, options)
+
+
+if __name__ == "__main__":
+    main()