Echo command in Dockerfile used to write aliases missing -e flag?

[NickCheng0921]

As of 2/2/25
In the Dockerfile for openworm,

RUN echo '\n\nalias cd..="cd .."\nalias h=history\nalias ll="ls -alt"' >> ~/.bashrc
doesn't seem to update bashrc properly

Running source ~/.bashrc throws the below error
root@1a2cf2d71234:/# source ~/.bashrc
bash: nnalias: command not found

As the aliases aren't written into the bashrc correctly

Instead, using -e interprets the string properly
RUN echo '\n\nalias cd..="cd .."\nalias h=history\nalias ll="ls -alt"' >> ~/.bashrc

~/.bashrc with -e
alias cd..='cd ..'
alias h='history'
alias ll='ls -alt'

~/.bashrc without -e
\n\nalias cd..="cd .."\nalias h=history\nalias ll="ls -alt"

[pgleeson]

Thanks for pointing this out @NickCheng0921. It seems versions of echo on different systems have different options, some support -e, others only support -n.

The base image used here is ubuntu 22.04, and this doesn't require the -e. To get round this all, I've changed the Dockerfile to use printf:

OpenWorm/Dockerfile

Line 121 in 8809c8c

RUN printf '\n\nalias cd..="cd .."\nalias h=history\nalias ll="ls -alt"\n' >> ~/.bashrc

[HussainAther]

This is a great example of how cross-platform behavior (especially with shell utilities like echo) can introduce silent bugs depending on the base image. Switching to printf is a clean and portable fix, great call @pgleeson.

This change not only ensures compatibility across environments (including stricter shells or non-GNU implementations), but also prevents confusing parsing issues for users jumping into the container expecting functional aliases.