Why Sponsor Oils? | source | all docs for version 0.21.0 | all versions | oilshell.org

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

Word Language

This chapter in the Oils Reference describes the word language for OSH and YSH.

Table of Contents

Formatting Typed Data as Strings

Expressions to Words

expr-sub

expr-splice

var-splice

Formatting Typed Data as Strings

ysh-printf

ysh-format

Quotes

osh-string

Single quotes
Double Quotes
C-style strings: $'\n'

TODO: elaborate

ysh-string

YSH strings in the word language are the same as in the expression language.

See ysh-string in chap-expr-lang.

triple-quoted

Triple-quoted in the word language are the same as in the expression language.

See triple-quoted in chap-expr-lang.

tagged-str

Not done.

Substitutions

command-sub

Executes a command and captures its stdout.

OSH has shell-compatible command sub like $(echo hi). If a trailing newline is returned, it's removed:

$ hostname
example.com

$ echo "/tmp/$(hostname)"
/tmp/example.com

YSH has spliced command subs, enabled by shopt --set parse_at. The reuslt is a List of strings, rather than a single string.

$ write -- @(echo foo; echo 'with spaces')
foo
with-spaces

The command's stdout parsed as the "J8 Lines" format, where each line is either:

An unquoted string, which must be valid UTF-8. Whitespace is allowed, but not other ASCII control chars.
A quoted J8 string (JSON style "" or J8-style b'' u'' '')
An ignored empty line

See J8 Notation for more details.

var-sub

Evaluates to the value of a variable:

$ x=X
$ echo $x ${x}
X X

arith-sub

Shell has C-style arithmetic:

$ echo $(( 1 + 2*3 ))
7