sh Files

This release drops support for Go 1.25 and includes many enhancements, particularly in the interpreter, which implements more shell features and fixes many divergences from Bash.

• cmd/shfmt
• Add --detect to find shell files by executable bit or shebang - [#944]
• syntax
• Add Preorder, an iterator over all nodes, complementing Walk
• Add encoding.TextUnmarshaler implementations for each operator type
• Support ${ foo;} and ${|foo;} inside double quotes - [#1368]
• Support array elements in {varname} redirects, like exec {fds[3]}>&- - [#719]
• Backslashes inside backquotes within double quotes escape double quotes - [#1083]
• Allow pound signs in associative array keys like ${args[cmd,#]} - [#1285]
• Don't treat # as the start of a comment inside [[ ]] tests - [#1326]
• Don't join then or do with a semicolon when heredocs are pending - [#1047]
• Print a space after ! in arithmetic expressions, avoiding history expansion - [#987]
• Space nested closing parentheses like the opening ones - [#876]
• Make SplitBraces reject malformed sequences and skip backslash escapes - [#1330]
• Zsh: support the ${=name}, ${~name}, and ${^name} prefixes - [#1238]
• Zsh: support the ;| case terminator and leading parentheses for globs - [#1293], [#1279]
• Zsh: parse subscript flag arguments as patterns, and allow [ globs in arrays - [#1278], [#1322]
• syntax/typedjson
• Encode operators as their syntax form, such as ">>", rather than integers - [#1321]
• Return errors rather than panicking on malformed input
• interp
• Add BashOpts to set Bash options like shopt - [#962]
• Add AccessHandler to control file access checks, used by -r and cd - [#1318]
• Add HandlerContext.LastExitStatus, and provide a HandlerContext to stat handlers
• Implement the help and times builtins, as well as $- - [#1398]
• Implement the ;& and ;;& case terminators - [#1391]
• Implement the -N test operator, and make -nt and -ot follow POSIX - [#1340]
• Support sparse indexed arrays such as a=([5]=x) - [#1373]
• Run files as shell scripts when exec fails with ENOEXEC - [#1065]
• Support empty here-documents, and don't expand quoted ones - [#1390]
• Support js/wasm, where subprocesses and pipes are unavailable
• Keep the redirections applied by exec with no arguments
• Only fire the exit trap when the shell exits, rather than after every Run
• expand
• Add BracesSeq with a config and error reporting, deprecating Braces
• Add Variable.Indexes to describe sparse indexed arrays
• Support integer bases in arithmetic - [#339]
• Short-circuit the arithmetic && and || operators - [#1371]
• Apply per-element operators to quoted array expansions like "${a[@]%o}" - [#1081]
• Make unquoted ${!arr[@]} consistent with the quoted form - [#672]
• Fix many divergences from Bash in arithmetic, string, and brace expansions
• Reject unsupported Zsh syntax rather than panicking - [#1363]
• pattern
• Treat an unmatched [ as a literal character, like Bash - [#1372]
• Fix panics and mismatches in bracket expressions, such as [![:space:]]
• fileutil
• Recognize dash shebangs as POSIX shell for -ln=auto - [#1307]

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Binaries built on go version go1.27.0 linux/amd64 with:

CGO_ENABLED=0 go build -trimpath -ldflags="-w -s"