London | 26-SDC-July | Kris Oldrini | Sprint 4 | Python Shell Tools

implement-shell-tools/cat/cat.py

@@ -0,0 +1,66 @@
+import argparse
+import sys
+
+parser = argparse.ArgumentParser(
+    prog="cat",
+    description="Prints the content of files"
+)
+
+parser.add_argument(
+    "-n",
+    "--number",
+    action="store_true",
+    help="Numbers all lines"
+)
+
+parser.add_argument(
+    "-b",
+    "--number-nonblank",
+    action="store_true",
+    help="Number non-empty lines"
+)
+
+parser.add_argument(
+    "paths",
+    nargs="+",
+    help="The file to print"
+)
+
+args = parser.parse_args()
+
+line_number = 1
+
+
+def number_lines(lines, line_number, include_blank_lines):
+    numbered_lines = []
+
+    for line in lines:
+        if include_blank_lines or line != "\n":
+            numbered_line = str(line_number).rjust(6) + "  " + line
+            numbered_lines.append(numbered_line)
+            line_number += 1
+        else:
+            numbered_lines.append(line)
+
+    return numbered_lines, line_number
+
+
+for path in args.paths:
+    with open(path, "r") as file:
+        lines = file.readlines()
+
+        if args.number_nonblank:
+            lines, line_number = number_lines(
+                lines,
+                line_number,
+                False
+            )
+        elif args.number:
+            lines, line_number = number_lines(
+                lines,
+                line_number,
+                True
+            )
+
+        output = "".join(lines)
+        sys.stdout.write(output)

implement-shell-tools/ls/ls.py

@@ -0,0 +1,74 @@
+import argparse
+import sys
+import os
+
+parser = argparse.ArgumentParser(
+    prog="ls",
+    description="List directory contents"
+)
+
+parser.add_argument(
+    "-1",
+    "--format",
+    action="store_true",
+    help="List one file per line"
+)
+
+parser.add_argument(
+    "-a",
+    "--all",
+    action="store_true",
+    help="Do not ignore entries starting with ."
+)
+
+parser.add_argument(
+    "paths",
+    nargs="*",
+    help="The file to print"
+)
+
+args = parser.parse_args()
+
+if args.format:
+    separator = "\n"
+else:
+    separator = "  "
+
+multiple_paths = len(args.paths) > 1
+
+file_paths = []
+directory_paths = []
+
+if len(args.paths) == 0:
+    args.paths.append(".")
+
+for path in args.paths:
+    if os.path.isfile(path):
+        file_paths.append(path)
+
+    elif os.path.isdir(path):
+        directory_paths.append(path)
+
+if len(file_paths) > 0:
+    sys.stdout.write(separator.join(file_paths) + "\n")
+
+for path in directory_paths:
+    if multiple_paths:
+        sys.stdout.write("\n" + path + ":\n")
+
+    entries = os.listdir(path)
+    entries.sort()
+
+    if args.all:
+        entries = [".", ".."] + entries
+
+    else:
+        visible_entries = []
+
+        for entry in entries:
+            if not entry.startswith("."):
+                visible_entries.append(entry)
+
+        entries = visible_entries
+
+    sys.stdout.write(separator.join(entries) + "\n")

implement-shell-tools/wc/wc.py

@@ -0,0 +1,120 @@
+import argparse
+import sys
+import os
+
+parser = argparse.ArgumentParser(
+    prog="wc",
+    description="Print newline, word, and byte counts for files"
+)
+
+parser.add_argument(
+    "-l",
+    "--lines",
+    action="store_true",
+    help="Print the newline counts"
+)
+
+parser.add_argument(
+    "-w",
+    "--words",
+    action="store_true",
+    help="Print the word counts"
+)
+
+parser.add_argument(
+    "-c",
+    "--bytes",
+    action="store_true",
+    help="Print the byte counts"
+)
+
+parser.add_argument(
+    "paths",
+    nargs="*",
+    help="The file to print"
+)
+
+args = parser.parse_args()
+
+total_line_count = 0
+total_word_count = 0
+total_byte_count = 0
+
+rows = []
+
+def get_counts(path):
+    with open(path, "r") as file:
+        content = file.readlines()
+
+        lines_count = len(content)
+
+        joined_content = "".join(content)
+
+        words = joined_content.split()
+        word_count = len(words)
+
+        byte_count = len(joined_content.encode())
+
+        return lines_count, word_count, byte_count
+
+
+def select_count(lines_count, word_count, byte_count):
+    selected_counts = []
+
+    if args.lines:
+        selected_counts.append(lines_count)
+
+    if args.words:
+        selected_counts.append(word_count)
+
+    if args.bytes:
+        selected_counts.append(byte_count)
+
+    if len(selected_counts) == 0:
+        selected_counts.append(lines_count)
+        selected_counts.append(word_count)
+        selected_counts.append(byte_count)
+
+    return selected_counts
+
+
+for path in args.paths:
+    lines_count, word_count, byte_count = get_counts(path)
+
+    total_line_count += lines_count
+    total_word_count += word_count
+    total_byte_count += byte_count
+
+    selected_counts = select_count(
+        str(lines_count),
+        str(word_count),
+        str(byte_count)
+    )
+
+    rows.append((selected_counts, path))
+
+if len(args.paths) > 1:
+    total_counts = select_count(
+        str(total_line_count),
+        str(total_word_count),
+        str(total_byte_count)
+    )
+    rows.append((total_counts, "total"))
+
+padding = max(
+    len(count)
+    for counts, _ in rows
+    for count in counts
+)
+
+output = []
+
+for counts, path in rows:
+    padded_counts = []
+
+    for count in counts:
+        padded_counts.append(count.rjust(padding))
+
+    output.append(" ".join(padded_counts) + " " + path)
+
+print("\n".join(output))