Glasgow | 6-SDC-Aug | Shreef Ibrahim | Sprint 4 | Implement shell tools in python

implement-shell-tools/cat/cat.py

@@ -0,0 +1,22 @@
+import argparse
+import sys
+
+parser = argparse.ArgumentParser(prog="cat")
+parser.add_argument("-n", action="store_true")
+parser.add_argument("-b", action="store_true")
+parser.add_argument("files", nargs="+")
+
+args = parser.parse_args()
+
+for file in args.files:
+    line_number = 1
+
+    with open(file) as f:
+        for line in f:
+            should_number = args.n or (args.b and line.strip())
+
+            if should_number:
+                print(f"{line_number:6}\t{line}", end="")
+                line_number += 1
+            else:
+                print(line, end="")

implement-shell-tools/ls/ls.py

@@ -0,0 +1,43 @@
+import argparse
+import os
+
+parser = argparse.ArgumentParser(prog="ls")
+parser.add_argument("-1", dest="one", action="store_true")
+parser.add_argument("-a", action="store_true")
+parser.add_argument("paths", nargs="*", default=["."])
+
+args = parser.parse_args()
+
+
+def get_files(path):
+    files = sorted(os.listdir(path))
+
+    if args.a:
+        return [".", ".."] + files
+
+    return [f for f in files if not f.startswith(".")]
+
+
+# Print all files first
+for path in args.paths:
+    if not os.path.isdir(path):
+        if args.one:
+            print(path)
+        else:
+            print(path, end="     ")
+print()
+
+# Print directories
+for path in args.paths:
+    if os.path.isdir(path):
+
+        if len(args.paths) > 1:
+            print(f"\n{path}:")
+
+        files = get_files(path)
+
+        if args.one:
+            for file in files:
+                print(file)
+        else:
+            print("   ".join(files))

implement-shell-tools/wc/wc.py

@@ -0,0 +1,54 @@
+import argparse
+
+parser = argparse.ArgumentParser(prog="wc")
+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("files", nargs="+")
+
+args = parser.parse_args()
+
+
+def format_counts(lines, words, chars):
+    if not args.l and not args.w and not args.c:
+        return f"{lines:8}{words:8}{chars:8}"
+
+    output = ""
+
+    if args.l:
+        output += f"{lines:8}"
+    if args.w:
+        output += f"{words:8}"
+    if args.c:
+        output += f"{chars:8}"
+
+    return output
+
+
+total_lines = 0
+total_words = 0
+total_chars = 0
+
+for file in args.files:
+    with open(file, "r") as f:
+        text = f.read()
+
+    lines = text.count("\n")
+
+    stripped = text.strip()
+    words = len(stripped.split()) if stripped else 0
+
+    chars = len(text.encode())
+
+    total_lines += lines
+    total_words += words
+    total_chars += chars
+
+    print(format_counts(lines, words, chars), file)
+
+
+if len(args.files) > 1:
+    print(
+        format_counts(total_lines, total_words, total_chars),
+        "total"
+    )