Why does cURL return error "(23) Failed writing body"?
MacosBashCurlOsx LionPipeMacos Problem Overview
It works ok as a single tool:
curl "someURL"
curl -o - "someURL"
but it doesn't work in a pipeline:
curl "someURL" | tr -d '\n'
curl -o - "someURL" | tr -d '\n'
it returns:
(23) Failed writing body
What is the problem with piping the cURL output? How to buffer the whole cURL output and then handle it?
Macos Solutions
Solution 1 - Macos
This happens when a piped program (e.g. grep) closes the read pipe before the previous program is finished writing the whole page.
In curl "url" | grep -qs foo, as soon as grep has what it wants it will close the read stream from curl. cURL doesn't expect this and emits the "Failed writing body" error.
A workaround is to pipe the stream through an intermediary program that always reads the whole page before feeding it to the next program.
E.g.
curl "url" | tac | tac | grep -qs foo
tac is a simple Unix program that reads the entire input page and reverses the line order (hence we run it twice). Because it has to read the whole input to find the last line, it will not output anything to grep until cURL is finished. Grep will still close the read stream when it has what it's looking for, but it will only affect tac, which doesn't emit an error.
Solution 2 - Macos
For completeness and future searches:
It's a matter of how cURL manages the buffer, the buffer disables the output stream with the -N option.
Example:
curl -s -N "URL" | grep -q Welcome
Solution 3 - Macos
Another possibility, if using the -o (output file) option - the destination directory does not exist.
eg. if you have -o /tmp/download/abc.txt and /tmp/download does not exist.
Hence, ensure any required directories are created/exist beforehand, use the --create-dirs option as well as -o if necessary
Solution 4 - Macos
You can do this instead of using -o option:
curl [url] > [file]
Solution 5 - Macos
The server ran out of disk space, in my case.
Check for it with df -k .
I was alerted to the lack of disk space when I tried piping through tac twice, as described in one of the other answers: https://stackoverflow.com/a/28879552/336694. It showed me the error message write error: No space left on device.
Solution 6 - Macos
So it was a problem of encoding. Iconv solves the problem
curl 'http://www.multitran.ru/c/m.exe?CL=1&s=hello&l1=1' | iconv -f windows-1251 | tr -dc '[:print:]' | ...
Solution 7 - Macos
I had the same error but from different reason. In my case I had (tmpfs) partition with only 1GB space and I was downloading big file which finally filled all memory on that partition and I got the same error as you.
Solution 8 - Macos
If you are trying something similar like source <( curl -sS $url ) and getting the (23) Failed writing body error, it is because sourcing a process substitution doesn't work in bash 3.2 (the default for macOS).
Instead, you can use this workaround.
source /dev/stdin <<<"$( curl -sS $url )"
Solution 9 - Macos
For me, it was permission issue. Docker run is called with a user profile but root is the user inside the container. The solution was to make curl write to /tmp since that has write permission for all users , not just root.
I used the -o option.
-o /tmp/file_to_download
Solution 10 - Macos
In my case, I was doing:
curl <blabla> | jq | grep <blibli>
With jq . it worked: curl <blabla> | jq . | grep <blibli>
Solution 11 - Macos
Trying the command with sudo worked for me. For example:
sudo curl -O -k 'https url here'
note: -O (this is capital o, not zero) & -k for https url.
Solution 12 - Macos
I encountered the same problem when doing:
curl -L https://packagecloud.io/golang-migrate/migrate/gpgkey | apt-key add -
The above query needs to be executed using root privileges.
Writing it in following way solved the issue for me:
curl -L https://packagecloud.io/golang-migrate/migrate/gpgkey | sudo apt-key add -
If you write sudo before curl, you will get the Failed writing body error.
Solution 13 - Macos
> I encountered this error message while trying to install varnish cache on ubuntu. The google search landed me here for the error (23) Failed writing body, hence posting a solution that worked for me.
The bug is encountered while running the command as root curl -L https://packagecloud.io/varnishcache/varnish5/gpgkey | apt-key add -
the solution is to run apt-key add as non root
curl -L https://packagecloud.io/varnishcache/varnish5/gpgkey | apt-key add -
Solution 14 - Macos
In Bash and zsh (and perhaps other shells), you can use process substitution (Bash/zsh) to create a file on the fly, and then use that as input to the next process in the pipeline chain.
For example, I was trying to parse JSON output from cURL using jq and less, but was getting the Failed writing body error.
# Note: this does NOT work
curl https://gitlab.com/api/v4/projects/ | jq | less
When I rewrote it using process substitution, it worked!
# this works!
jq "" <(curl https://gitlab.com/api/v4/projects/) | less
Note: jq uses its 2nd argument to specify an input file
Bonus: If you're using jq like me and want to keep the colorized output in less, use the following command line instead:
jq -C "" <(curl https://gitlab.com/api/v4/projects/) | less -r
(Thanks to Kowaru for their explanation of why Failed writing body was occurring. However, their solution of using tac twice didn't work for me. I also wanted to find a solution that would scale better for large files and tries to avoid the other issues noted as comments to that answer.)