{"version":"2.1.318","anchor":"bash-heredoc-on-stdin-teaching-macos-binbash-only-flag-d","canonical_anchor":"bash-heredoc-on-stdin-teaching-macos-binbash-only-flag-d","heading":"New macOS-only Bash tool behaviour for heredocs, on by default","tier":"notice","area":"Bash Tool","scope":"individual","heads_up":false,"url":"https:\/\/changelogs.core-directive.com\/v\/2.1.318\/e\/bash-heredoc-on-stdin-teaching-macos-binbash-only-flag-d","release_url":"https:\/\/changelogs.core-directive.com\/v\/2.1.318","markdown":"### New macOS-only Bash tool behaviour for heredocs, on by default\n\nOn macOS with \/bin\/bash, the Bash tool now checks a remote switch that defaults to on for a change involving heredocs on input\n\n**Unclear.** It is not clear what the Bash tool does differently when this check is true.\n\n**What**\n\nClaude Code now has a check that the Bash tool uses. The Bash tool is how Claude runs shell commands. The check is true only when all of these hold:\n\n- You are on macOS.\n\n- Your shell is `\/bin\/bash`.\n\n- A remote switch is on. It counts as on unless it is switched off remotely.\n\nThe check concerns heredocs, a way of passing several lines of text into a command as its input.\n\n**Why**\n\nThis looks like macOS-only Bash tool behaviour that is on by default, so Mac users running `\/bin\/bash` are the ones it can affect.\n\n- Flag `tengu_mossy_anvil`: Not enough to say (read for one account on one subscription tier against v2.1.318; this account: no value returned, anonymous baseline: no value returned, compiled default: on) These values were read against a different version of Claude Code, so treat them as the nearest reading available instead of one taken on this release.\n- Area: Bash Tool\n- Tier: You'll notice\n- Useful: 2\/5\n- Signal: 2\/5\n- Scope: individual\n- Heads-up: no"}