London | 26-jul-SDC | Shaghayegh far| Sprint 4 | Implement shell tools with python

implement-shell-tools/cat/cat.py

@@ -0,0 +1,39 @@
+import argparse
+
+def print_file(filename, mode):
+    with open(filename, "r") as file:
+        line_number = 1
+
+        for line in file:
+            if mode == "number_all":
+                print(f"{line_number} {line}", end="")
+                line_number += 1
+
+            elif mode == "number_nonempty":
+                if line.strip() == "":
+                    print(line, end="")
+                else:
+                    print(f"{line_number} {line}", end="")
+                    line_number += 1
+
+            else:
+                print(line, end="")
+
+
+parser = argparse.ArgumentParser()
+group = parser.add_mutually_exclusive_group()
+group.add_argument("-n", action="store_true", help="Number all lines")
+group.add_argument("-b", action="store_true", help="Number non-empty lines")
+parser.add_argument("filenames", nargs="+")
+
+args = parser.parse_args()
+
+if args.n:
+    mode = "number_all"
+elif args.b:
+    mode = "number_nonempty"
+else:
+    mode = "none"
+
+for filename in args.filenames:
+    print_file(filename, mode)

implement-shell-tools/ls/ls.py

@@ -0,0 +1,65 @@
+import sys
+import os
+
+
+# Get arguments from the command line
+arguments = sys.argv[1:]
+
+
+# Check if -1 flag exists
+show_one_per_line = False
+
+if "-1" in arguments:
+    show_one_per_line = True
+    arguments.remove("-1")
+
+
+# Check if -a flag exists
+show_all_files = False
+
+if "-a" in arguments:
+    show_all_files = True
+    arguments.remove("-a")
+
+
+# If no path is given, use current directory
+if len(arguments) == 0:
+    path = "."
+else:
+    path = arguments[0]
+
+
+# Check if the path exists
+if not os.path.exists(path):
+    print(f"ls: cannot access '{path}': No such file or directory")
+    sys.exit()
+
+
+# If the path is a file, just print the file name
+if os.path.isfile(path):
+    print(path)
+
+
+# If the path is a folder, list its contents
+else:
+
+    files = os.listdir(path)
+
+
+    # Remove hidden files unless -a was used
+    if not show_all_files:
+        files = [
+            file for file in files
+            if not file.startswith(".")
+        ]
+
+
+    # Print one file per line
+    if show_one_per_line:
+        for file in files:
+            print(file)
+
+
+    # Normal ls behaviour
+    else:
+        print("  ".join(files))

implement-shell-tools/wc/wc.py

@@ -0,0 +1,60 @@
+
+import sys
+
+arguments = sys.argv[1:]
+count_lines = False
+count_words = False
+count_characters = False
+filenames = []
+
+for argument in arguments:
+    if argument == "-l":
+        count_lines = True
+    elif argument == "-w":
+        count_words = True
+    elif argument == "-c":
+        count_characters = True
+    else:
+        filenames.append(argument)
+
+if not count_lines and not count_words and not count_characters:
+    count_lines = True
+    count_words = True
+    count_characters = True
+
+total_lines = 0
+total_words = 0
+total_characters = 0
+
+for filename in filenames:
+    with open(filename, "r") as file:
+        content = file.read()
+
+    lines = len(content.splitlines())
+    words = len(content.split())
+    characters = len(content)
+
+    total_lines += lines
+    total_words += words
+    total_characters += characters
+
+    answer = ""
+    if count_lines:
+        answer += str(lines) + " "
+    if count_words:
+        answer += str(words) + " "
+    if count_characters:
+        answer += str(characters) + " "
+
+    print(answer + filename)
+
+if len(filenames) > 1:
+    total = ""
+    if count_lines:
+        total += str(total_lines) + " "
+    if count_words:
+        total += str(total_words) + " "
+    if count_characters:
+        total += str(total_characters) + " "
+
+    print(total + "total")