exec - Run commands and open, close, or copy descriptors

exec [ -c ] [ command [ argument ... ] ]

Description

The exec utility replaces qsh with command without creating a new process. The specified arguments are arguments to command. Any redirections affect the current environment.

When a command is not specified, any redirections are processed in the current environment. Any file descriptors greater than 2 that are opened by a redirection are not inherited when qsh invokes another program.

Options

-c

Run command with an empty set of environment variables.

Operands

Each argument is assigned in order to the positional parameters of command.

Exit Status

Zero if no command is specified. Otherwise it does not return to qsh.

Related information

• command - Run a simple command
• dot (.) - Run commands in current environment
• eval - Construct command by concatenating arguments
• nohup - Run utility without hangups
• print - Write output
• read - Read a line from standard input

1. Open a file for reading on descriptor 5:

   exec 5<$HOME/input
   

2. Close descriptor 5:

   exec 5<&-