ix.io is a plain-text pastebin usable directly from the shell with curl, with no client tool needed.

echo "some output" | curl -F 'f:1=<-' ix.io          # paste stdin, get back a URL
dmesg | curl -F 'f:1=<-' ix.io                        # paste command output directly
curl -F 'f:1=<-' ix.io < error.log                    # paste a file's contents

The response is a plain URL you can share. Treat anything pasted there as public: do not paste secrets, credentials, or private data. For code with syntax highlighting and longer retention, a service with access controls (a private GitHub Gist, an internal pastebin) is often more appropriate for work contexts.