9.3 Standard shell commands
The standard shell commands are divided into special built-in commands and regular built-in commands, as shown below. A built-in command is one that is included as part of the shell, and is executed by the shell itself.
Special built-in commands
If a special built-in command's syntax is invalid, it exits the shell that is executing the command.
Regular built-in commands
Even if a regular built-in command's syntax is invalid, it does not exit the shell that is executing the command.
- Organization of this section
9.3.8 continue command (interrupts loop processing and returns to the beginning of the loop)
9.3.9 echo command (outputs what is specified in arguments to the standard output)
9.3.10 eval command (concatenates arguments into a command and executes it)
9.3.17 let command (evaluates the values of arithmetic expressions)
9.3.19 pwd command (outputs the path of the current directory)
9.3.20 read command (reads from the standard input and stores the input in variables)
9.3.22 return command (returns from a function or an external script)
9.3.23 set command (sets shell options, creates an array, or displays variable values)
9.3.25 test command (determines the value of a conditional expression)
9.3.26 times command (displays the amount of CPU time used by the shell)
9.3.27 trap command (specifies the action when signals and forced termination requests are received)
9.3.29 typeset command (declares explicitly the attributes and values of variables and functions)
9.3.30 ulimit command (sets limits on system resources) (UNIX only)
9.3.31 umask command (sets the access permissions for creating a new file) (UNIX only)
9.3.33 unset command (unsets variable values and attributes)
9.3.35 whence command (displays how character strings would be interpreted if used as commands)