London | 25-SDC-July | Franklin Kamela | Sprint 4 | Feature/shell-tools-python

.vscode/settings.json

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+{
+    "githubPullRequests.ignoredPullRequestBranches": [
+        "main"
+    ]
+}

implement-shell-tools/cat/cat.py

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+#!/usr/bin/env python3
+import argparse
+
+# implement-shell-tools/cat/cat.py
+def main():
+    parser = argparse.ArgumentParser(
+    prog="cat",
+    description="Implements a simple version of the 'cat' command to read and display file contents."
+    )
+
+    parser.add_argument("-n", help="Number lines", action="store_true")
+    parser.add_argument("-b", help="Number non-blank lines", action="store_true")
+    parser.add_argument("path", nargs="+", help="The file to search")
+
+    args = parser.parse_args()
+
+    line_number = 1
+    non_blank_line_number = 1
+
+    for file_path in args.path:
+        try:
+            with open(file_path, 'r') as file:
+                content = file.read()
+                lines = content.split("\n")
+
+                for i, line in enumerate(lines):
+                    if i == len(lines) - 1 and line == "":  # Skip the last empty line if it exists
+                        break
+                    prefix = ""
+                    if args.n:
+                        prefix = str(line_number).rjust(6) + " "
+                    elif args.b and line != "":
+                        prefix = str(non_blank_line_number).rjust(6) + " "
+                    print(prefix + line)
+                    line_number += 1
+                    if line != "":
+                        non_blank_line_number += 1
+
+        except FileNotFoundError:
+            print(f"cat: {file_path}: No such file or directory")
+        except Exception as e:
+            print(f"cat: {file_path}: {e}")
+
+if __name__ == "__main__":
+    main()

implement-shell-tools/ls/ls.py

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+# implement-shell-tools/ls/ls.py
+import argparse
+import os
+import sys
+import shutil
+import math
+
+def print_columns(items, force_single_column=False):
+    """Print items in columns unless -1 is passed or output is not a tty."""
+    if force_single_column or not sys.stdout.isatty():
+        for item in items:
+            print(item)
+        return
+
+    # Get terminal width
+    term_width = shutil.get_terminal_size((80, 20)).columns
+
+    if not items:
+        return
+
+    # Longest filename length + spacing
+    max_len = max(len(f) for f in items) + 2
+    cols = max(1, term_width // max_len)
+    rows = math.ceil(len(items) / cols)
+
+    for r in range(rows):
+        row_items = []
+        for c in range(cols):
+            i = c * rows + r
+            if i < len(items):
+                row_items.append(items[i].ljust(max_len))
+        print("".join(row_items).rstrip())
+
+def main():
+    parser = argparse.ArgumentParser(
+    prog="ls",
+    description="Implements a simple version of the 'ls' command to list files in a directory."
+    )
+
+    parser.add_argument("-1", help="List one file per line", action="store_true")
+    parser.add_argument("-a", help="Include hidden files", action="store_true")
+    parser.add_argument("directory", nargs="?", default=".", help="The directory to search")
+
+    args = parser.parse_args()
+
+    try:
+        if os.path.isdir(args.directory):
+            files = os.listdir(args.directory)
+
+            if not args.a:
+                files = [f for f in files if not f.startswith(".")]
+
+            files = sorted(files)
+
+            print_columns(files, force_single_column=args.__dict__["1"])
+        else:
+            # If it's a file, just print the name
+            print(args.directory)
+
+    except FileNotFoundError:
+        print(f"ls: {args.directory}: No such file or directory", file=sys.stderr)
+    except Exception as e:
+        print(f"ls: {args.directory}: {e}", file=sys.stderr)
+
+if __name__ == "__main__":
+    main()

implement-shell-tools/wc/wc.py

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+import argparse
+import sys
+
+# implement-shell-tools/wc/wc.py
+def wc_file(path):
+    """Return (lines, words, bytes) for a given file."""
+    with open(path, "r", encoding="utf-8") as f:
+        text = f.read()
+    lines = text.count("\n")
+    if text and not text.endswith("\n"):
+        lines += 1  # Count last line if it doesn't end with newline
+    words = len(text.split())
+    chars = len(text.encode("utf-8"))  # byte count
+    return lines, words, chars
+
+def format_counts(lines, words, chars, args, label):
+    """Return formatted output string for wc counts."""
+    parts = []
+    if args.l:
+        parts.append(str(lines).rjust(8))
+    if args.w:
+        parts.append(str(words).rjust(8))
+    if args.c:
+        parts.append(str(chars).rjust(8))
+    if label:
+        parts.append(label)
+    return " ".join(parts)
+
+def main():
+    parser = argparse.ArgumentParser(
+    prog="wc",
+    description="Implements a simple version of the 'wc' command to count lines, words, and characters in text files."
+    )
+
+    parser.add_argument("-l", action="store_true", help="Count lines")
+    parser.add_argument("-w", action="store_true", help="Count words")
+    parser.add_argument("-c", action="store_true", help="Count characters")
+    parser.add_argument("path", nargs="+", help="The files to read")
+
+    args = parser.parse_args()
+
+    if not (args.l or args.w or args.c):
+        args.l = args.w = args.c = True  # Default to all counts if none specified
+
+    total_lines = total_words = total_chars = 0
+
+    for file_path in args.path:
+        try:
+            lines, words, chars = wc_file(file_path)
+            total_lines += lines
+            total_words += words
+            total_chars += chars
+
+            print(format_counts(lines, words, chars, args, file_path))
+
+        except FileNotFoundError:
+            print(f"wc: {file_path}: No such file or directory", file=sys.stderr)
+        except Exception as e:
+            print(f"wc: {file_path}: {e}", file=sys.stderr)
+
+    if len(args.path) > 1:
+        print(format_counts(total_lines, total_words, total_chars, args, "total"))
+
+if __name__ == "__main__":
+    main()