Problem in cat part in #NI6 in golang

Challenges
1

I’m stuck on Stage #NI6

I’ve tried, parsing the arguments on my own, which helped me to pass the echo part, but I can’t pass the cat part.

Here are my logs:

[compile] Moved ./.codecrafters/run.sh → ./your_program.sh
[compile] Compilation successful.
[tester::#NI6] Running tests for Stage #NI6 (Quoting - Single quotes)
[tester::#NI6] [setup] export PATH=/tmp/pineapple/mango/pineapple:$PATH
[tester::#NI6] Running ./your_program.sh
[tester::#NI6] [setup] echo -n "pear raspberry." > "/tmp/cow/f   88"
[tester::#NI6] [setup] echo -n "banana strawberry." > "/tmp/cow/f   11"
[tester::#NI6] [setup] echo "raspberry mango." > "/tmp/cow/f   42"
[your-program] $ echo 'example shell'
[your-program] example shell
[tester::#NI6] ✓ Received expected response
[your-program] $ echo shell     world
[your-program] shell world
[tester::#NI6] ✓ Received expected response
[your-program] $ echo 'hello     script' 'world''example' shell''test
[your-program] hello     script worldexample shelltest
[tester::#NI6] ✓ Received expected response
[your-program] $ cat '/tmp/cow/f   88' '/tmp/cow/f   11' '/tmp/cow/f   42'
[your-program] cat: /tmp/cow/f   88 /tmp/cow/f   11 /tmp/cow/f   42: No such file or directory
[tester::#NI6] ^ Line does not match expected value.
[tester::#NI6] Expected: "pear raspberry.banana strawberry.raspberry mango."
[tester::#NI6] Received: "cat: /tmp/cow/f   88 /tmp/cow/f   11 /tmp/cow/f   42: No such file or directory"
[your-program] 2026/01/03 08:16:48 exit status 1
[tester::#NI6] Assertion failed.
[tester::#NI6] Test failed

And here’s a snippet of my code:

				data, err := Echo(cmdList)
				if err != nil {
					log.Fatal(err)
				}
				execute := exec.Command(cmdList[0], data)

this is how i handle cat and other commands, not echo, echo one is handled separately below, but I can create for cat, echo:

		if cmdList[0] == "echo" {
			if cmd == "echo" {
				continue
			}

			data, err := Echo(cmdList)
			if err != nil {
				log.Fatal("Error", err)
			}
			fmt.Println(data)
			continue

		}

And here is my Echo function

func Echo(cmdList []string) (string, error) {
	content := fmt.Sprint(cmdList[1:])
	realContent := content[1 : len(content)-1]

	opened := false
	// doubleOpened := false
	var result string
	var quotesContent string
	var withoutQuotesContent string
	emitted := false
	inArgument := false

	for _, v := range realContent {
		if v == '\'' {
			//fmt.Println("bar")
			opened = !opened
		}
		//		if v == 39 {
		//			doubleOpened = !doubleOpened
		//		}
		if opened && v != '\'' {
			if withoutQuotesContent != "" {
				if emitted && !inArgument {
					result += " "
				}
				result += strings.Join(strings.Fields(withoutQuotesContent), " ")
				withoutQuotesContent = ""
				emitted = true
				inArgument = true
			}
			quotesContent += string(rune(v))
		} else if !opened {
			if v == '\'' {
				// then it is just closed
				if quotesContent != "" {
					if emitted && !inArgument {
						result += " "
					}
					result += quotesContent
					quotesContent = ""
					emitted = true
					inArgument = true
					//				fmt.Printf("--->%v\n", result)
					//				fmt.Println("baz")
				}
			} else {
				//treat it as normal thing
				if v == ' ' {
					inArgument = false
				}
				withoutQuotesContent += string(rune(v))
				//				fmt.Println("foo")
				// fmt.Println(withoutQuotesContent)
			}
		}
	}
	//	fmt.Println(quotesContent)
	//	fmt.Printf("%q\n", withoutQuotesContent)

	if withoutQuotesContent != "" {
		if emitted && !inArgument {
			result += " "
		}
		result += strings.Join(strings.Fields(withoutQuotesContent), " ")
	}

	return result, nil
}

Any help will appreciated, if above is not clear, please let me know in replies. Thanks.

2

Hi, thanks for your post!

I’m currently out of the office for the holidays and will be back on January 5. I’ll get back to you as soon as possible once I return.

4

I don’t know Go, but it looks like exec.Command takes a “splatted list” of args: func Command(name string, arg ...string) *Cmd.

Most crafters probably parses the command into a list of tokens. Then the command or built-ins process them. You; however, make an interesting choice to use Echo to essentially parse. But from what I can tell you only return a single string in result which you then pass as the single splatted argument to Command(cmdList[0], data).

Now the error makes if we consider that cat is reporting cat: <filename>: No such file or directory. Your filename is the single string /tmp/cow/f 88 /tmp/cow/f 11 /tmp/cow/f 42 and not three individual paths.

Edit: since Posix/Linux, unlike say Windows, give programs a list of args, that is what argcand argv is you actually need the ability to split the input into separate pieces. A good starting point for this is your Echo function, but look at the places where you “append” a piece and consider whether that is a separate argument instead.

5

I have confusion, cat '/tmp/fox/f 81' '/tmp/fox/f 56' '/tmp/fox/f 70' are these 3 files or 6 files? I can’t understand, also what i believe /tmp/fox/f 81 should give it as it is rather than /tmp/fox/f 81, so how cat is parsing them?

6

solved by ignoring or removing the single quotes in the cmdList[1:] no need of Echo in cat here, i guess same will be applied in double quotes too.

1 Like
7

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