London | 25-SDC-Nov | Zohreh Kazemianpour | Sprint 4 | Implement Shell Tools-Python

.gitignore

@@ -1 +1,2 @@
 node_modules
+prep/

implement-shell-tools/cat/cat.py

@@ -0,0 +1,50 @@
+import sys
+import argparse
+
+# Setup argument parser
+parser = argparse.ArgumentParser(
+    prog="cat",
+    description="Concatenate and display files"
+)
+
+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 lines only")
+parser.add_argument("paths", nargs='+', help="Files to read")
+
+args = parser.parse_args()
+
+line_number = 0  # Shared counter across all files
+
+# Process each file
+for path in args.paths:  # LEVEL 1: for loop starts
+    with open(path, "r") as f:  # LEVEL 2: inside for loop
+        content = f.read()  # LEVEL 3: inside with block
+
+    # Check if numbering is needed
+    if args.number:  # LEVEL 2: inside for loop
+        lines = content.split("\n")  # LEVEL 3: inside if
+        numbered_lines = []
+
+        for index, line in enumerate(lines):  # LEVEL 3: inside if
+            line_number = line_number + 1  # LEVEL 4: inside inner for
+            numbered_line = f"{line_number:6}\t{line}"
+            numbered_lines.append(numbered_line)
+
+        print("\n".join(numbered_lines))  # LEVEL 3: inside if
+
+    elif args.number_nonblank:  # LEVEL 2: inside for loop
+        lines = content.split("\n")  # LEVEL 3: inside elif
+        numbered_lines = []
+
+        for line in lines:  # LEVEL 3: inside elif
+            if line.strip() == "":  # LEVEL 4: inside inner for
+                numbered_lines.append(line)
+            else:
+                line_number = line_number + 1
+                numbered_line = f"{line_number:6}\t{line}"
+                numbered_lines.append(numbered_line)
+
+        print("\n".join(numbered_lines))
+
+    else:  # LEVEL 2: inside for loop
+        print(content)  # LEVEL 3: inside else

implement-shell-tools/ls/ls.py

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+import os
+import argparse
+
+# Setup argument parser
+parser = argparse.ArgumentParser(
+    prog="ls",
+    description="Lists contents of a directory"
+)
+
+parser.add_argument("-1", dest="one_column", action="store_true", help="List one file per line")
+parser.add_argument("-a", "--all", action="store_true", help="Include hidden files")
+parser.add_argument("path", nargs='?', default=".", help="Directory to list (default: current directory)")
+
+args = parser.parse_args()
+
+# List directory contents
+files = os.listdir(args.path)
+
+# Filter out hidden files unless -a flag is used
+if not args.all:
+    files = [f for f in files if not f.startswith('.')]
+
+for file in files:
+    print(file)

implement-shell-tools/wc/wc.py

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+import argparse
+
+# Setup argument parser
+parser = argparse.ArgumentParser(
+    prog="wc",
+    description="Count lines, words, and characters"
+)
+parser.add_argument("paths", nargs='+', help="Files to count")
+parser.add_argument("-l", "--lines", action="store_true", help="Count lines only")
+parser.add_argument("-w", "--words", action="store_true", help="Count words only")
+parser.add_argument("-c", "--chars", action="store_true", help="Count characters only")
+
+args = parser.parse_args()
+
+# Track totals
+total_lines = 0
+total_words = 0
+total_chars = 0
+
+for path in args.paths:
+    # Read the file
+    with open(path, "r") as f:
+        content = f.read()
+
+    # Count lines, words, characters
+    lines = len(content.rstrip('\n').split('\n'))
+    words = len(content.split())
+    chars = len(content)
+
+    # Add to totals
+    total_lines += lines
+    total_words += words
+    total_chars += chars
+
+    if args.lines:
+        print(f"{lines:8} {path}")
+    elif args.words:
+        print(f"{words:8} {path}")
+    elif args.chars:
+        print(f"{chars:8} {path}")
+    else:
+        print(f"{lines:8}{words:8}{chars:8} {path}")  
+
+
+# Print totals if multiple files
+if len(args.paths) > 1:
+    if args.lines:
+        print(f"{total_lines:8} total")
+    elif args.words:
+        print(f"{total_words:8} total")
+    elif args.chars:
+        print(f"{total_chars:8} total")
+    else:
+        print(f"{total_lines:8}{total_words:8}{total_chars:8} total")        
+