London | 25-SDC-July | Eyuel Abraham | Sprint 4 | Implement shell tool python

.gitignore

@@ -1 +1,2 @@
 node_modules
+.venv/

implement-shell-tools/cat/my_cat.py

@@ -0,0 +1,68 @@
+import argparse
+import sys
+
+parser = argparse.ArgumentParser(
+    description="Reads and prints one or more files, optionally numbering lines continuously"
+)
+parser.add_argument("paths", nargs='+', help="One or more file paths")
+parser.add_argument("-n", "--number", action="store_true", help="Number all output lines")
+parser.add_argument("-b", "--number-nonblank", action="store_true", help="Number non-empty output lines")
+
+args = parser.parse_args()
+
+file_paths = args.paths
+number_nonblank = args.number_nonblank
+number_all = args.number and not number_nonblank
+
+
+total_lines = 0
+total_nonblank_lines = 0
+
+for path in file_paths:
+    try:
+        with open(path, 'r', encoding='utf-8') as f:
+            lines = f.readlines()
+            total_lines += len(lines)
+            total_nonblank_lines += sum(1 for line in lines if line.strip())
+    except Exception as e:
+        print(f'Error reading file "{path}": {e}', file=sys.stderr)
+        sys.exit(1)
+
+
+if number_nonblank:
+    max_digits = len(str(total_nonblank_lines))
+elif number_all:
+    max_digits = len(str(total_lines))
+
+line_number = 1
+
+
+for path in file_paths:
+    try:
+        with open(path, 'r', encoding='utf-8') as f:
+            lines = f.readlines()
+
+        if number_nonblank:
+            for line in lines:
+                if line.strip() == "":
+                    print()
+                else:
+                    num_str = str(line_number).rjust(max_digits)
+                    print(f"{num_str}\t{line.rstrip()}")
+                    line_number += 1
+
+        elif number_all:
+            for line in lines:
+                num_str = str(line_number).rjust(max_digits)
+                print(f"{num_str}\t{line.rstrip()}")
+                line_number += 1
+
+        else:
+            for line in lines:
+                print(line, end='')
+            if lines and not lines[-1].endswith('\n'):
+                print()
+
+    except Exception as e:
+        print(f'Error reading file "{path}": {e}', file=sys.stderr)
+        sys.exit(1)

implement-shell-tools/ls/my_ls.py

@@ -0,0 +1,60 @@
+import os
+import sys
+import stat
+import argparse
+
+parser = argparse.ArgumentParser(
+    description="List files in a directory (simplified ls implementation)"
+)
+parser.add_argument("paths", nargs="*", default=["."], help="One or more file or directory paths")
+parser.add_argument("-l", "--longList", action="store_true", help="Long listing format")
+parser.add_argument("-a", "--all", action="store_true", help="Include hidden files")
+
+parser.add_argument("-1", "--singleColumn", action="store_true", help="List one file per line") 
+args = parser.parse_args()
+
+file_paths = args.paths
+show_long = args.longList
+show_all = args.all
+force_single_column = args.singleColumn 
+
+def format_permissions(mode):
+    return stat.filemode(mode)
+
+for input_path in file_paths:
+    try:
+        if not os.path.exists(input_path):
+            raise FileNotFoundError(f'No such file or directory: {input_path}')
+
+        if os.path.isfile(input_path):
+            if show_long:
+                file_stat = os.stat(input_path)
+                perms = format_permissions(file_stat.st_mode)
+                size = str(file_stat.st_size).rjust(6)
+                print(f"{perms}  {size}  {input_path}")
+            else:
+                print(input_path)
+
+        elif os.path.isdir(input_path):
+            entries = os.listdir(input_path)
+            if not show_all:
+                entries = [e for e in entries if not e.startswith(".")]
+
+            # Optional: sort entries for consistent output
+            entries.sort()  # (optional for predictable output)
+
+            for entry in entries:
+                full_path = os.path.join(input_path, entry)
+                entry_stat = os.stat(full_path)
+                if show_long:
+                    perms = format_permissions(entry_stat.st_mode)
+                    size = str(entry_stat.st_size).rjust(6)
+                    print(f"{perms}  {size}  {entry}")
+                elif force_single_column:
+                    print(entry)
+                else:
+                    print(entry)  
+
+    except Exception as e:
+        print(f'Error reading "{input_path}": {e}', file=sys.stderr)
+        sys.exit(1)

implement-shell-tools/wc/my_wc.py

@@ -0,0 +1,68 @@
+import os
+import sys
+import argparse
+
+# CLI argument parsing
+parser = argparse.ArgumentParser(description="Simplified implementation of wc")
+parser.add_argument("paths", nargs="*", default=["."], help="One or more file or directory paths")
+parser.add_argument("-l", "--line", action="store_true", help="Count lines")
+parser.add_argument("-w", "--word", action="store_true", help="Count words")
+parser.add_argument("-c", "--character", action="store_true", help="Count characters")
+
+args = parser.parse_args()
+
+# If no flags are set, show all
+show_all = not (args.line or args.word or args.character)
+
+# Count content in a string
+def count_content(content):
+    lines = content.splitlines()
+    words = content.strip().split()
+    characters = len(content)
+    return len(lines), len(words), characters
+
+# Format output line based on flags
+def format_output(lines, words, chars, label):
+    parts = []
+    if args.line or show_all:
+        parts.append(f"{lines:8}")
+    if args.word or show_all:
+        parts.append(f"{words:8}")
+    if args.character or show_all:
+        parts.append(f"{chars:8}")
+    parts.append(label)
+    return " ".join(parts)
+
+# Totals for multiple files
+total = {"lines": 0, "words": 0, "characters": 0}
+file_count = 0
+
+for input_path in args.paths:
+    try:
+        if os.path.isdir(input_path):
+            print(f"{input_path} is a directory. Skipping.")
+            continue
+
+        with open(input_path, "r", encoding="utf-8") as f:
+            content = f.read()
+
+        lines, words, characters = count_content(content)
+
+        total["lines"] += lines
+        total["words"] += words
+        total["characters"] += characters
+        file_count += 1
+
+        print(format_output(lines, words, characters, input_path))
+
+    except Exception as e:
+        print(f'Error reading "{input_path}": {e}', file=sys.stderr)
+
+# Print totals if more than one file processed
+if file_count > 1:
+    print(format_output(
+        total["lines"],
+        total["words"],
+        total["characters"],
+        "total"
+    ))