> ## Documentation Index > Fetch the complete documentation index at: https://docs.syntblaze.com/llms.txt > Use this file to discover all available pages before exploring further. # Bash Conditional OR List A conditional OR list is a sequence of one or more pipelines separated by the `||` control operator. It implements short-circuit evaluation, executing a subsequent command in the sequence strictly if the preceding AND/OR list evaluates to a non-zero (failure) exit status. ```bash theme={"dark"} command1 || command2 [|| command3 ...] ``` ## Execution Mechanics The shell evaluates a conditional OR list from left to right. 1. `command1` is executed, and the shell captures its exit status. 2. If `command1` returns an exit status of `0` (success), the shell short-circuits the evaluation. `command2` and any subsequent commands in the contiguous OR list are skipped and not executed. 3. If `command1` returns a non-zero exit status (failure), the shell proceeds to execute `command2`. 4. This evaluation model propagates down the chain until a command returns `0` or the end of the list is reached. ## Exit Status The overall exit status of a conditional OR list is determined by the exit status of the **last command executed** within that list. * If any command in the sequence evaluates to `0`, the list terminates immediately, and the exit status of the entire list is `0`. * If all commands in the sequence fail, the list evaluates to the non-zero exit status of the final command in the chain. ## Precedence and Associativity The `||` control operator shares equal precedence with the conditional AND operator (`&&`). Both operators are strictly left-associative. When `||` and `&&` are mixed in a single un-grouped command string, the shell parses and evaluates them sequentially from left to right. Because of left-associativity, the execution of a subsequent command depends on the exit status of the **entire preceding AND/OR list** evaluated so far, not just the single pipeline immediately preceding the operator. ```bash theme={"dark"} # command3 executes if the evaluated result of 'command1 || command2' is 0 command1 || command2 && command3 ``` In the structure above, if `command1` succeeds (returns `0`), `command2` is skipped. However, the exit status of the preceding list (`command1 || command2`) is `0`. Consequently, the `&&` operator sees a successful preceding list, causing `command3` to execute. To override default left-associativity and enforce specific evaluation precedence, commands must be explicitly grouped using compound commands, such as subshells `( ... )` or brace groups `{ ...; }`. ```bash theme={"dark"} # Grouping alters the evaluation hierarchy command1 || { command2 && command3; } ```
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