Python Implementation

Author: Priscilla-EM

implement-shell-tools/cat/mycat.py

@@ -0,0 +1,39 @@
+import argparse
+import glob
+
+parser = argparse.ArgumentParser(
+    prog="mycat",
+    description="Outputs the content of the given file(s), like the cat command",
+)
+
+parser.add_argument("-n", help="Number all lines", action="store_true")
+parser.add_argument("-b", help="Number all non-blank lines", action="store_true")
+parser.add_argument("path", help="The file to display(allowing wildcards)", nargs="+")
+
+args = parser.parse_args()
+
+file_list = []
+for path in args.path:
+    file_list.extend(glob.glob(path))
+
+line_number = 1
+
+for filename in file_list:
+    try:
+        with open(filename, "r") as f:
+            for line in f:
+                stripped = line.rstrip("\n")
+
+                if args.b:
+                    if stripped:
+                        print(f"{line_number:>6}\t{stripped}")
+                        line_number += 1
+                    else:
+                        print("")
+                elif args.n:
+                    print(f"{line_number:>6}\t{stripped}")
+                    line_number += 1
+                else:
+                    print(line, end="")
+    except FileNotFoundError:
+        print(f"mycat: {filename}: No such file or directory")

implement-shell-tools/ls/myls.py

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+import argparse
+import os
+
+parser = argparse.ArgumentParser(
+    prog="myls",
+    description="List directory contents like the ls command"
+)
+
+parser.add_argument("-1", dest="one_per_line", action="store_true",
+                    help="List one file per line")
+parser.add_argument("-a", dest="all_files", action="store_true",
+                    help="Include hidden files starting with '.'")
+parser.add_argument("path", nargs="?", default=".", help="Directory to list (default: current directory)")
+
+args = parser.parse_args()
+
+try:
+    entries = os.listdir(args.path)
+except FileNotFoundError:
+    print(f"my_ls: cannot access '{args.path}': No such file or directory")
+    exit(1)
+
+if not args.all_files:
+    entries = [e for e in entries if not e.startswith('.')]
+
+entries.sort()
+
+if args.one_per_line:
+    for entry in entries:
+        print(entry)
+else:
+    print("  ".join(entries))

implement-shell-tools/wc/mywc.py

@@ -0,0 +1,72 @@
+import argparse
+import glob
+import os
+
+def count_file(file_path, count_lines=False, count_words=False, count_bytes=False):
+    lines = words = bytes_count = 0
+    with open(file_path, "r", encoding="utf-8", errors="ignore") as f:
+        for line in f:
+            lines += 1
+            words += len(line.split())
+    bytes_count = os.path.getsize(file_path)
+
+    if not (count_lines or count_words or count_bytes):
+        return lines, words, bytes_count
+
+    return (
+        lines if count_lines else None,
+        words if count_words else None,
+        bytes_count if count_bytes else None
+    )
+
+def main():
+    parser = argparse.ArgumentParser(description="count lines, words, and bytes like the wc command")
+    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 bytes")
+    parser.add_argument("path", nargs="+", help="Files to count")
+
+    args = parser.parse_args()
+
+    total_lines = total_words = total_bytes = 0
+    file_list = []
+    for pattern in args.path:
+        file_list.extend(glob.glob(pattern))
+
+    for file_path in file_list:
+        counts = count_file(file_path, args.l, args.w, args.c)
+
+        if not (args.l or args.w or args.c):
+            lines, words, bytes_count = counts
+            print(f"{lines:>7} {words:>7} {bytes_count:>7} {file_path}")
+            total_lines += lines
+            total_words += words
+            total_bytes += bytes_count
+        else:
+            count_strings = []
+            if counts[0] is not None:
+                count_strings.append(f"{counts[0]:>7}")
+                total_lines += counts[0]
+            if counts[1] is not None:
+                count_strings.append(f"{counts[1]:>7}")
+                total_words += counts[1]
+            if counts[2] is not None:
+                count_strings.append(f"{counts[2]:>7}")
+                total_bytes += counts[2]
+            print(" ".join(count_strings), file_path)
+
+    if len(file_list) > 1:
+        if not (args.l or args.w or args.c):
+            print(f"{total_lines:>7} {total_words:>7} {total_bytes:>7} total")
+        else:
+            total_strings = []
+            if args.l:
+                total_strings.append(f"{total_lines:>7}")
+            if args.w:
+                total_strings.append(f"{total_words:>7}")
+            if args.c:
+                total_strings.append(f"{total_bytes:>7}")
+            print(" ".join(total_strings), "total")
+
+if __name__ == "__main__":
+    main()