> ## 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 Writable Check The `-w` operator is a unary file test operator in Bash used within conditional expressions to evaluate whether a specified file exists and grants write permission to the effective user ID (EUID) of the process executing the script. **Syntax** ```bash theme={"dark"} [ -w FILE_PATH ] [[ -w FILE_PATH ]] test -w FILE_PATH ``` **Evaluation Mechanics** * **True (Exit Status `0`):** The operand `FILE_PATH` resolves to an existing file, directory, or special file, AND the operating system grants write access to the current process. * **False (Exit Status `1`):** The operand `FILE_PATH` does not exist, OR it exists but the current process lacks write access. **Technical Characteristics** * **Permission Resolution:** The operator evaluates the standard POSIX permission bits (User, Group, Other) and Access Control Lists (ACLs) against the EUID and Effective Group ID (EGID) of the executing shell. * **Directory Semantics:** When applied to a directory, `-w` evaluates to true if the process has permission to modify the directory's index (i.e., the ability to create, delete, or rename files within that directory). * **Symbolic Links:** The `-w` operator dereferences symbolic links. It evaluates the write permissions of the ultimate target file, not the link itself. * **Filesystem State:** The operator respects the mount state of the underlying filesystem at the kernel level. If a file's permission bits allow writing, but the filesystem is mounted as read-only (`ro`), `-w` will evaluate to false.

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