London | 25-SDC-July | Mikiyas Gebremichael | Sprint 4 | Implement Shell Tool Python

implement-shell-tools/cat/cat.py

@@ -0,0 +1,52 @@
+import argparse
+import sys
+
+
+def read_files(paths):
+    lines = []
+    for path in paths:
+        try:
+            with open(path, "r", encoding="utf-8") as f:
+                lines.extend(f.read().splitlines())
+        except OSError as e:
+            print(f"Error reading {path}: {e}", file=sys.stderr)
+            sys.exit(1)
+    return lines
+
+
+def main():
+    parser = argparse.ArgumentParser(
+        prog="display-content-of-a-file",
+        description="cat is used to display the content of a file or print the content of a file.",
+    )
+
+    parser.add_argument("-n", action="store_true", help="number output lines")
+    parser.add_argument("-b", action="store_true", help="number non-empty output lines")
+    parser.add_argument("paths", nargs="+", help="The file path(s) to process")
+
+    options = parser.parse_args()
+
+    lines = read_files(options.paths)
+
+    if options.b:
+        line_num = 1
+        for line in lines:
+            if line.strip():
+                print(f"{line_num:6} {line}")
+                line_num += 1
+            else:
+                print(line)
+
+    elif options.n:
+        for i, line in enumerate(lines, start=1):
+            print(f"{i:6} {line}")
+
+    else:
+        for line in lines:
+            print(line)
+
+
+if __name__ == "__main__":
+    main()
+
+#python3 cat.py -b sample-files/*  

implement-shell-tools/ls/ls.py

@@ -0,0 +1,37 @@
+import argparse  #for parsing command-line arguments and options
+import os        #to interact with the os for listing files and handling paths
+import sys       #Allows interaction with the Py runtime env like reading/writing output,exiting.
+
+
+def list_directory(directory, show_all, one_per_line):
+    try:
+        files = os.listdir(directory)
+    except Exception as e:
+        print(f"ls: cannot access '{directory}': {e}", file=sys.stderr)
+        return 1
+
+    if not show_all:
+        files = [f for f in files if not f.startswith('.')]
+    files.sort()
+
+    if one_per_line:
+        for file in files:
+            print(file)
+    else:
+        print(' '.join(files))
+
+    return 0
+
+def main():
+    parser = argparse.ArgumentParser(description="A simplified ls implementation.")
+    parser.add_argument('-1', dest='one_per_line', action='store_true', help='list one file per line')
+    parser.add_argument('-a', action='store_true', help='include hidden files')
+    parser.add_argument('directory', nargs='?', default='.', help='directory to list (default: current directory)')
+
+    args = parser.parse_args()
+
+    exit_code = list_directory(args.directory, args.a, args.one_per_line)
+    sys.exit(exit_code)
+
+if __name__ == "__main__":
+    main()

implement-shell-tools/wc/wc.py

@@ -0,0 +1,49 @@
+import argparse
+import sys
+import os
+
+def format_output(lines, words, bytes_, label, options):
+    output = ""
+    if not (options.l or options.w or options.c):
+        output += f"{lines:8}{words:8}{bytes_:8}"
+    else:
+        if options.l:
+            output += f"{lines:8}"
+        if options.w:
+            output += f"{words:8}"
+        if options.c:
+            output += f"{bytes_:8}"
+    return f"{output} {label}"
+
+def main():
+    parser = argparse.ArgumentParser(description="Count lines, words, and bytes in files (like 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="+", help="files to read")
+    options = parser.parse_args()
+
+    total_lines = total_words = total_bytes = 0
+
+    for file_path in options.files:
+        try:
+            with open(file_path, "r", encoding="utf-8") as f:
+                data = f.read()
+
+            lines = data.count("\n")
+            words = len(data.split())
+            bytes_ = len(data.encode("utf-8"))
+
+            total_lines += lines
+            total_words += words
+            total_bytes += bytes_
+
+            print(format_output(lines, words, bytes_, os.path.basename(file_path), options))
+        except Exception as e:
+            print(f"Error reading {file_path}: {e}", file=sys.stderr)
+
+    if len(options.files) > 1:
+        print(format_output(total_lines, total_words, total_bytes, "total", options))
+
+if __name__ == "__main__":
+    main()