Why Sponsor Oils? | source | all docs for version 0.19.0 | all versions | oilshell.org

Warning: Work in progress! Leave feedback on Zulip or Github if you'd like this doc to be updated.

Global Shell Options

This chapter in the Oils Reference describes global shell options for OSH and YSH.

Option Groups

strict:all

Option in this group disallow problematic or confusing shell constructs. The resulting script will still run in another shell.

shopt --set strict:all  # turn on all options
shopt -p strict:all     # print their current state

ysh:upgrade

Options in this group enable Oil features that are less likely to break existing shell scripts.

For example, parse_at means that @myarray is now the operation to splice an array. This will break scripts that expect @ to be literal, but you can simply quote it like '@literal' to fix the problem.

shopt --set ysh:upgrade   # turn on all options
shopt -p ysh:upgrade      # print their current state

ysh:all

Enable the full Oil language. This includes everything in the ysh:upgrade group.

shopt --set ysh:all     # turn on all options
shopt -p ysh:all        # print their current state

Strictness

strict_control_flow

Disallow break and continue at the top level, and disallow empty args like return $empty.

strict_tilde

Failed tilde expansions cause hard errors (like zsh) rather than silently evaluating to ~ or ~bad.

strict_word_eval

TODO

strict_nameref

When strict_nameref is set, undefined references produce fatal errors:

declare -n ref
echo $ref  # fatal error, not empty string
ref=x      # fatal error instead of decaying to non-reference

References that don't contain variables also produce hard errors:

declare -n ref='not a var'
echo $ref  # fatal
ref=x      # fatal

parse_ignored

For compatibility, Oil will parse some constructs it doesn't execute, like:

return 0 2>&1  # redirect on control flow

When this option is disabled, that statement is a syntax error.

ysh:upgrade

parse_at

TODO

parse_brace

TODO

parse_paren

TODO

parse_raw_string

Allow the r prefix for raw strings in command mode:

echo r'\'  # a single backslash

Since shell strings are already raw, this means that Oil just ignores the r prefix.

command_sub_errexit

TODO

process_sub_fail

TODO

sigpipe_status_ok

If a process that's part of a pipeline exits with status 141 when this is option is on, it's turned into status 0, which avoids failure.

SIGPIPE errors occur in cases like 'yes | head', and generally aren't useful.

simple_word_eval

TODO:

YSH Breaking

copy_env

parse_equals

Errors

Globbing

nullglob

Normally, when no files match a glob, the glob itself is returned:

$ echo L *.py R  # no Python files in this dir
L *.py R

With nullglob on, the glob expands to no arguments:

shopt -s nullglob
$ echo L *.py R
L R

(This option is in GNU bash as well.)

dashglob

Do globs return results that start with -? It's on by default in bin/osh, but off when Oil is enabled.

Turning it off prevents a command like rm * from being confused by a file called -rf.

$ touch -- myfile -rf

$ echo *
-rf myfile

$ shopt -u dashglob
$ echo *
myfile

Debugging

Interactive

Other Option