| The following options can be specified only on the command line: | -c command-string | the shell executes the command(s) contained in command-string | | -i | interactive mode - see below | | -l login shell | see below interactive mode | | -s | the shell reads commands from standard input; all non-option arguments are positional parameters | | -r | restricted mode - see below |
In addition to the above, the options described in the set builtin command can also be used on the command line. If neither the -c nor the -s options are specified, the first non-option argument specifies the name of a file the shell reads commands from; if there are no non-option arguments, the shell reads commands from standard input. The name of the shell (i.e., the contents of the $0) parameter is determined as follows: if the -c option is used and there is a non-option argument, it is used as the name; if commands are being read from a file, the file is used as the name; otherwise the name the shell was called with (i.e., argv[0]) is used. A shell is interactive if the -i option is used or if both standard input and standard error are attached to a tty. An interactive shell has job control enabled (if available), ignores the INT, QUIT and TERM signals, and prints prompts before reading input (see PS1 and PS2 parameters). For non-interactive shells, the trackall option is on by default (see set command below). A shell is restricted if the -r option is used or if either the basename of the name the shell is invoked with or the SHELL parameter match the pattern *r*sh (e.g., rsh, rksh, rpdksh, etc.). The following restrictions come into effect after the shell processes any profile and $ENV files: the cd command is disabled the SHELL, ENV and PATH parameters can't be changed command names can't be specified with absolute or relative paths the -p option of the command built-in can't be used redirections that create files can't be used (i.e., >, >|, >>, <>)
A shell is privileged if the -p option is used or if the real user-id or group-id does not match the effective user-id or group-id (see getuid(2), getgid(2)). A privileged shell does not process $HOME/.profile nor the ENV parameter (see below), instead the file /etc/suid_profile is processed. Clearing the privileged option causes the shell to set its effective user-id (group-id) to its real user-id (group-id). If the basename of the name the shell is called with (i.e., argv[0]) starts with - or if the -l option is used, the shell is assumed to be a login shell and the shell reads and executes the contents of /etc/profile and $HOME/.profile if they exist and are readable. If the ENV parameter is set when the shell starts (or, in the case of login shells, after any profiles are processed), its value is subjected to parameter, command, arithmetic and tilde substitution and the resulting file (if any) is read and executed. If ENV parameter is not set (and not null) and pdksh was compiled with the DEFAULT_ENV macro defined, the file named in that macro is included (after the above mentioned substitutions have been performed). The exit status of the shell is 127 if the command file specified on the command line could not be opened, or non-zero if a fatal syntax error occurred during the execution of a script. In the absence of fatal errors, the exit status is that of the last command executed, or zero, if no command is executed. |
