Post a message to a Slack channel

slackpost

#!/bin/bash

# Usage: slackpost <token> <channel> <message>

# Enter the name of your slack host here - the thing that appears in your URL:
# https://slackhost.slack.com/
slackhost=PUT_YOUR_HOST_HERE

token=$1

if [[ $token == "" ]]
then
        echo "No token specified"
        exit 1
fi

shift
channel=$1
if [[ $channel == "" ]]
then
        echo "No channel specified"
        exit 1
fi

shift

text=$*

if [[ $text == "" ]]
then
        echo "No text specified"
        exit 1
fi

escapedText=$(echo $text | sed 's/"/\"/g' | sed "s/'/\'/g" )
json="{\"channel\": \"#$channel\", \"text\": \"$escapedText\"}"

curl -s -d "payload=$json" "https://$slackhost.slack.com/services/hooks/incoming-webhook?token=$token"

I made some my one. :)
https://gist.github.com/andkirby/67a774513215d7ba06384186dd441d9e
It allows to use ENV vars for channels/webhookURL.
Also it can push a message to several channels.

I get an error illegal option pipe fail

This is pure awesome <3

adding capability to read multiple lines from stdin / pipe

#!/bin/bash

# Usage: slackpost "<webhook_url>" "<channel>" "<username>" "<message>"
# also (echo $RANDOM; echo $RANDOM) |slackpost "<channel>" "<username>"

# ------------
webhook_url=$1
if [[ $webhook_url == "" ]]
then
        echo "No webhook_url specified"
        exit 1
fi

# ------------
shift
channel=$1
if [[ $channel == "" ]]
then
        echo "No channel specified"
        exit 1
fi

# ------------
shift
username=$1
if [[ $username == "" ]]
then
        echo "No username specified"
        exit 1
fi

# ------------
shift

text=$*

if [[ $text == "" ]]
then
while IFS= read -r line; do
  #printf '%s\n' "$line"
  text="$text$line\n"
done
fi


if [[ $text == "" ]]
then
        echo "No text specified"
        exit 1
fi

escapedText=$(echo $text | sed 's/"/\"/g' | sed "s/'/\'/g" )

json="{\"channel\": \"$channel\", \"username\":\"$username\", \"icon_emoji\":\"ghost\", \"attachments\":[{\"color\":\"danger\" , \"text\": \"$escapedText\"}]}"

curl -s -d "payload=$json" "$webhook_url"

bash in not the default in a couple of distros

#!/usr/bin/env bash

# Usage: slackpost "<webhook_url>" "<channel>" "<username>" "<message>"
# also (echo $RANDOM; echo $RANDOM) |slackpost "<channel>" "<username>"

# ------------
webhook_url=$1
if [[ $webhook_url == "" ]]
then
        echo "No webhook_url specified"
        exit 1
fi

# ------------
shift
channel=$1
if [[ $channel == "" ]]
then
        echo "No channel specified"
        exit 1
fi

# ------------
shift
username=$1
if [[ $username == "" ]]
then
        echo "No username specified"
        exit 1
fi

# ------------
shift

text=$*

if [[ $text == "" ]]
then
while IFS= read -r line; do
  #printf '%s\n' "$line"
  text="$text$line\n"
done
fi


if [[ $text == "" ]]
then
        echo "No text specified"
        exit 1
fi

escapedText=$(echo $text | sed 's/"/\"/g' | sed "s/'/\'/g" )

json="{\"channel\": \"$channel\", \"username\":\"$username\", \"icon_emoji\":\"ghost\", \"attachments\":[{\"color\":\"danger\" , \"text\": \"$escapedText\"}]}"

curl -s -d "payload=$json" "$webhook_url"

Thank you all for the updates!
I was happy to use this as a fast and short solution, but found that it had multiple shortcomings, and the mandatory options made it painful to write a quick one liner to pipe all my output to slack.

If anyone is interested, i created a new version starting from the updates uploaded here, although it ended up as a complete rewrite with a much simpler API, proper JSON escaping and STDIN handling and optional configs to overwrite the default channel, bot name, etc.
Available here: http://github.com/a-sync/slackr

Another good alternative i found: https://github.com/course-hero/slacktee

Can anybody tell how to send message to the specific user?
bash slackpost webhook channel message - works
bash slackpost webhook @user message - Doesn't work. It says "channel_not_found"

Ask Linux system to send the traditional Chinese message to slack, and it will change to the code! How do you deal with it? Thx

@PetroPliuta - You may have found the answer to your question, but when targeting a user, you have to use their id instead of their name.
Example: "<@U3BV0GGY3>" or "U3BV0GGY3" depending on the API usage

In Slack: Click the user, then click their name and go to "View 's profile", then click the Down Arrow next to "Message" and you'll see "Copy member id".

You can also see this if you visit the following link (while you're logged into slack), click your name next to the "user" field and click "Test Method". This will show you a bunch of information about the user.
https://api.slack.com/methods/users.info/test

Here's a version which uses argument flags:

#!/usr/bin/env bash

# Usage: slackpost -w <webhook_url> -c <channel> -u <username> -m <message> [-a <alert_type>]
# Usage: echo <message> | slackpost -w <webhook_url> -c <channel> -u <username> [-a <alert_type>]

# exit immediately if a command exits with a non-zero status
set -e

# error if variable referenced before being set
set -u

# produce failure return code if any command fails in pipe
set -o pipefail

# accepted values: good, warning, danger
alert_type=""
channel=""
message=""
username=""
webhook_url=""

# colon after var means it has a value rather than it being a bool flag
while getopts 'a:c:m:u:w:' OPTION; do
  case "$OPTION" in
    a)
      alert_type="$OPTARG"
      ;;
    c)
      channel="$OPTARG"
      ;;
    m)
      message="$OPTARG"
      ;;
    u)
      username="$OPTARG"
      ;;
    w)
      webhook_url="$OPTARG"
      ;;
    ?)
      echo "script usage: $(basename $0) {-c channel} {-m message} {-u username} {-w webhook} [-a alert_type]" >&2
      exit 1
      ;;
  esac
done
shift "$(($OPTIND -1))"

# exit if channel not provided
if [[ -z "$channel" ]]
then
  echo "No channel specified"
  exit 1
fi

# read piped data as message if message argument is not provided
if [[ -z "$message" ]]
then
  message=$*

  while IFS= read -r line; do
    message="$message$line\n"
  done
fi

# exit if username not provided
if [[ -z "$username" ]]
then
  echo "No username specified"
  exit 1
fi

# exit if webhook not provided
if [[ -z "$webhook_url" ]]
then
  echo "No webhook_url specified"
  exit 1
fi

# escape message text
escapedText=$(echo $message | sed 's/"/\"/g' | sed "s/'/\'/g")

# create JSON payload
json="{\"channel\": \"$channel\", \"username\":\"$username\", \"icon_emoji\":\"ghost\", \"attachments\":[{\"color\":\"$alert_type\" , \"text\": \"$escapedText\"}]}"

# fire off slack message post
curl -s -d "payload=$json" "$webhook_url"

Can you explain for posting slash command using api ?

I should upload my version, it's updated to use the API better ...

Don't add the payload key before json variable.
And add the token in the headers.

curl -v \
	-H 'Content-Type:application/json; charset=utf-8' \
	-H 'Authorization: Bearer xoxp-XXXXXX-XXXX-XXXXXXXX \
	--data "$json" \
	"$slackwebhook"