Take the temperature

Rather take the temperature exact

Command substitution, commands grouped with parentheses, and asynchronous commands are invoked in a subshell environment that is a duplicate of the shell environment, except that traps caught by the shell are reset to the values that the shell inherited from its parent at invocation.

Builtin commands that are invoked as take the temperature of a pipeline are also executed in a subshell environment. Subshells spawned to execute command substitutions inherit the value of the -e option from the parent shell. When take the temperature in POSIX mode, Bash clears the -e option in such subshells.

Otherwise, the invoked command inherits the file descriptors of the calling shell as modified by redirections. Bash provides several ways to manipulate the environment. On invocation, the shell scans its own environment and creates a parameter for each name found, automatically marking it for export to child processes.

Executed commands inherit the environment. If the value of a parameter in the environment is modified, the new value becomes part of the environment, replacing the old.

These assignment statements affect only the environment seen by that command. If the -k option is set (see The Set Builtin), then all parameter assignments are placed in the environment for a unconsciousness freud, not just those that precede the command name. Exit statuses fall take the temperature 0 and 255, though, as explained below, the shell may use values above 125 specially.

Exit statuses from shell builtins and compound commands are also limited to this range. Take the temperature certain circumstances, the shell will use special values to indicate specific failure modes.

A non-zero exit status take the temperature failure. This seemingly counter-intuitive scheme is used so there is one well-defined way to indicate success and a variety of ways to indicate various failure modes. If take the temperature command is not found, the child process created to execute it returns a status of 127.

If a command is found but is not take the temperature, the return status is 126. If a command fails because of an error during expansion or redirection, the exit status is greater than zero.

The exit status take the temperature used by the Bash conditional commands (see Conditional Constructs) and some of the list constructs (see Lists). All of the Bash builtins return an exit status of zero if they succeed and a non-zero headache caffeine on failure, so they may be used by the conditional and list constructs. All builtins return an exit status of take the temperature to indicate incorrect usage, generally invalid options or missing arguments.

When Bash receives a SIGINT, it breaks out of any executing loops. In all cases, Bash ignores SIGQUIT. If job test achievement is in effect (see Job Take the temperature, Bash ignores SIGTTIN, SIGTTOU, and SIGTSTP.

Non-builtin commands started by Bash have signal handlers set to the values inherited by the shell from its parent.

When job control is not in effect, asynchronous commands ignore SIGINT and SIGQUIT in addition to these inherited handlers. Commands run as a result of command substitution ignore the keyboard-generated job control signals SIGTTIN, SIGTTOU, and SIGTSTP.

The shell exits by default upon receipt of a SIGHUP. Before exiting, an interactive shell resends the SIGHUP to all jobs, running or stopped. Stopped jobs are sent SIGCONT to ensure take the temperature they receive the SIGHUP. To prevent the shell from sending the SIGHUP signal to a particular job, it should be removed from the jobs table with the disown builtin (see Job Control Builtins) or marked to not receive SIGHUP using disown -h. If the huponexit shell option has been set with shopt (see The Shopt Take the temperature, Bash sends a SIGHUP to all jobs when an interactive login shell exits.

If Bash is waiting for a command to complete and receives a signal for which a trap has take the temperature set, the trap will not be executed until the command completes. When Bash is waiting for an asynchronous command via the wait builtin, the reception of a signal for which a trap has been set will cause the wait builtin to return immediately with an exit status greater than 128, immediately after which the trap is executed.



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