How to send emoji via bash script to Telegram bot using curl?

Question

I'm trying to send an emoji/emoticon to my Telegram bot using a bash script. This bash script calls the Telegram API as follows:

curl -s -X POST 'https://api.telegram.org/'$API'/sendMessage' -F chat_id=$chat -F text=$text

Since the bash script isn't unicode, I cannot simply copy/paste the emojis from the web. Therefore I tried using the UTF-8 emoji variants, but the backslash character keeps getting escaped.

The expected json output should be as follows: "text":"\ud83d\udd14"

Instead, this is what I get:

Input: $text = \xF0\x9F\x98\x81 JSON Output = "text":"\\xF0\\x9F\\x98\\x81\\"

Input: $text = u'\U0001F604' JSON Output = "text": "u'\\U0001F604'\"

Input: $text = \U0001F514 JSON Output = "text":"\\U0001F514"

Input: $text = "(1f600)" JSON Output = "text":"\"(1f600)\""

Input: $text = \ud83d\ude08 JSON Output = "text":"\\ud83d\\ude08"

Input: $text = \\\ud83d\\\udd14 JSON Output = "text":"\\\\\\ud83d\\\\\\udd14"

What is the correct syntax to send an emoji using a bash script and curl to my Telegram bot?

Thank you very much!

Yonne

If you're trying to generate JSON, let a tool written to handle JSON, like jq, figure out how to encode your string. – Crowell

BTW, what do you mean, "the bash script isn't unicode"? If you need to fix your editor settings, that's a problem with your text editor's configuration, and can be fixed from there. UTF-8 is a perfectly valid encoding to use for your script itself. – Crowell

Maybe I'm mixing things up, but I am using nano via SSH on a stripped down Unix environment (Synology NAS). If i copy/paste an emoticon from the Web into my SSH session, I get two question marks as a result. Hence i thought it was an encoding issue. – Yonne

Hmm. What terminal are you using for the SSH session? Are you sure that's UTF-8 capable, and using an appropriate font? – Crowell

I am using Rebex, but it appears that the encoding was set to some ISO-xxxx standard. After switching it to utf 8, I am able to copy/paste emoticons, yet I still have to declare them as variable first for them to be processed properly (i.e. not getting escaped) by the telegram api. – Yonne

Answer 1

Generating JSON For The Telegram API

If your question is about JSON encoding, let jq figure it out for you:

s='🔔'  ## or s=$'\360\237\224\224'

json=$(jq -anc --arg id "$chat" --arg s "$s" '{"chat_id": $id, "text": $s}')
curl -X POST -H "Content-Type: application/json" -d "$json" \
  "https://api.telegram.org/$API/sendMessage"

---

From JSON To String Literal

In bash 4.0 or newer, the shell itself can be asked to give you an ASCII-printable literal string which will correspond to a multi-byte character.

LC_ALL=C printf "s=%q\n" "$(jq -r . <<<'"\ud83d\udd14"')"

...will output:

s=$'\360\237\224\224'

---

From String Literal To JSON

To go in the other direction:

s=$'\360\237\224\224'
jq -anM --arg s "$s" '$s'

...emits as output:

"\ud83d\udd14"

Crowell

How the bell did you post that bell? – Wrought

@hek2mgl, I got the bell from jq -r . <<<'"\ud83d\udd14"', consuming the literal JSON string the OP put in the question. – Crowell

Many thanks for your super quick answer and example. I am going to try this out tomorrow. I am not sure if jq is installed on my environment, but if not I'll fall back to your second example. Thank you very much! I'll let you know how it goes. – Yonne

Hmm. If you don't have JQ, I'd be tempted to use Python rather than bash (since any remotely-recentish Python interpreter will have a JSON parser/generator built-in). That's doubly true if your messages are going to be coming from tooling that you don't directly control -- you don't need a text string ending in, say ", "sendVideo": "http://example.com/spam.m4v to be able to create new JSON fields rather than being correctly escaped as data. – Crowell

Many many thanks for your detailed answer! Both approaches worked (i.e. the jq approach and the 'convert to String Literal manually approach) for me. I spent almost 2 hours on getting something simple like this to work. Thanks again for the help! – Yonne

Is there a way to have the emoji inside the string instead of a separate var? eg json=$(jq -anc --arg id "$chat" --arg s "$'\360\237\224\224'" '{"chat_id": $id, "text": $s}' – Forgiving

@Stormenet, that example would work fine if you didn't have double quotes around the ANSI C-like string. Make it --arg s $'\360\237\224\224' – Crowell

I wasn't clear with my intent, can we do this around existing text, something like --arg s "This is an emoji: $'\360\237\224\224' and this is some more text..." since the latter isn't working here. – Forgiving

@Forgiving --arg s $'This is an emoji: \360\237\224\224 and this is some more text...' -- or you can switch quoting styles within your string by ending the double quotes and starting the ANSI C-like string, then if you want to switch back to double quotes ending the C-like string and starting double quotes again. This isn't really a jq question, it's just about how quoting works in bash in general. – Crowell

Answer 2

You can use echo -e '\U0001F514' for get emoji

curl -F "text=`echo -e '\U0001F514'` - it's a bell" "https://api.telegram.org/$API/sendMessage?chat_id=$chat"

or $'\U0001F514'

curl -F "text="$'\U0001F514'" - it's a bell" "https://api.telegram.org/$API/sendMessage?chat_id=$chat"

Infect

thx @Infect I was thinking the same as you by using "echo -e" and it worked for me. – Ramage

Boo, hiss re: echo -e; even the POSIX standard for echo says to use printf instead (see the APPLICATION USAGE and RATIONALE sections). There's also an excellent answer on the Unix & Linux question Why is printf better than echo? – Crowell