> ## 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 Disown Job
The `disown` command is a Bash shell builtin that removes a specified job from the shell's internal job control table. By removing the job from this table, the shell relinquishes tracking of the process, ensuring the shell will not broadcast a `SIGHUP` (Hangup) signal to that process if the shell receives a `SIGHUP` or terminates under specific configurations.
```bash theme={"dark"}
disown [-ar] [-h] [jobspec ...]
```
## Technical Mechanics
When a process is executed in the background (e.g., appended with `&` or suspended and resumed via `bg`), Bash assigns it a job specification (`jobspec`) and tracks it in an internal array. Bash broadcasts a `SIGHUP` to all tracked child processes in this array under two specific conditions:
1. The shell itself receives a `SIGHUP` (such as when the controlling terminal emulator is closed).
2. The shell is an interactive login shell terminating normally, and the `huponexit` shell option is enabled.
Executing `disown` alters this state in one of two ways, depending on the flags provided: it either completely excises the process from the job table, or it modifies the job's internal flags to bypass the `SIGHUP` broadcast while maintaining its presence in the table.
## Parameters and Flags
* **`jobspec`**: The job identifier (e.g., `%1`, `%2`). If omitted, `disown` defaults to the current job (represented by `%+` or `%%`).
* **`-h`**: Retains the job in the job control table but sets a flag preventing the shell from sending `SIGHUP` to it. The job remains visible to the `jobs` command.
* **`-a`**: Applies the `disown` operation to all jobs currently in the job table.
* **`-r`**: Restricts the operation to running jobs only, ignoring any jobs that are currently stopped (suspended).
## State Transition Example
```bash theme={"dark"}
# 1. Process is spawned in the background
sleep 300 &
# Output: [1] 14592
# 2. Process is tracked in the job table
jobs
# Output: [1]+ Running sleep 300 &
# 3. Process is excised from the job table
disown %1
# 4. Job table is now empty; shell will not send SIGHUP to PID 14592
jobs
# Output: (empty)
```
## I/O Stream Behavior
`disown` operates strictly on signal propagation and job tracking; it does **not** detach the process from the controlling terminal's file descriptors.
If a disowned process attempts to read from `stdin` or write to `stdout`/`stderr` after the controlling terminal is destroyed, the process will encounter an I/O error (typically resulting in a `SIGPIPE` or immediate termination). Furthermore, closing the terminal emulator itself may cause the terminal line discipline to send a `SIGHUP` directly to the session leader and its foreground process group, independent of the shell's job control mechanisms.
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