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 +1,37 @@
+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 = 1  # Shared counter across all files
+
+for path in args.paths:
+    with open(path, "r") as f:
+
+        lines = f.read().splitlines()
+
+    output = []
+    for line in lines:
+        if args.number_nonblank:
+            if line.strip():
+                output.append(f"{line_number:6}\t{line}")
+                line_number += 1
+            else:
+                output.append(line)
+        elif args.number:
+            output.append(f"{line_number:6}\t{line}")
+            line_number += 1
+        else:
+            output.append(line)
+
+    print("\n".join(output))

implement-shell-tools/ls/ls.py

@@ -0,0 +1,30 @@
+import os
+import argparse
+
+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("paths", nargs='*', default=["."], help="Directories to list")
+
+args = parser.parse_args()
+
+for path in args.paths:
+    if len(args.paths) > 1:
+        print(f"{path}:")
+
+    try:
+        files = os.listdir(path)
+        if not args.all:
+            files = [f for f in files if not f.startswith('.')]
+
+        files.sort()
+
+        sep = "\n" if args.one_column else "  "
+        print(sep.join(files))
+
+        if len(args.paths) > 1:
+            print()
+
+    except FileNotFoundError:
+        print(f"ls: cannot access '{path}': No such file or directory")

implement-shell-tools/wc/wc.py

@@ -0,0 +1,42 @@
+import argparse
+
+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")
+parser.add_argument("-w", "--words", action="store_true")
+parser.add_argument("-c", "--chars", action="store_true")
+
+args = parser.parse_args()
+
+# If no flags are provided, the default behavior is to show all three
+show_all = not (args.lines or args.words or args.chars)
+
+total_stats = [0, 0, 0] # lines, words, chars
+
+for path in args.paths:
+    with open(path, "r") as f:
+        content = f.read()
+
+    stats = [
+        len(content.splitlines()), 
+        len(content.split()), 
+        len(content)
+    ]
+
+    for i in range(3):
+        total_stats[i] += stats[i]
+
+    output = []
+    if args.lines or show_all: output.append(f"{stats[0]:8}")
+    if args.words or show_all: output.append(f"{stats[1]:8}")
+    if args.chars or show_all: output.append(f"{stats[2]:8}")
+
+    print(f"{''.join(output)} {path}")
+
+if len(args.paths) > 1:
+    total_output = []
+    if args.lines or show_all: total_output.append(f"{total_stats[0]:8}")
+    if args.words or show_all: total_output.append(f"{total_stats[1]:8}")
+    if args.chars or show_all: total_output.append(f"{total_stats[2]:8}")
+
+    print(f"{''.join(total_output)} total")