|
|
values they had upon entrance to the shell). If
arg is the null string, this signal is ignored by the shell and by the commands it invokes.
sigspec is either a signal name defined in
<signal.h>, or a signal number. If sigspec is
EXIT (0), the command arg is executed on exit from the shell. With no arguments,
trap prints the list of commands associated with each signal number. The
_l option causes the shell to print a list of signal names and their corresponding numbers. An argument of
— disables option checking for the rest of the arguments. Signals ignored upon entry
to the shell cannot be trapped or reset. Trapped signals are reset to their original
values in a child process when it is created. The return status is
False if either the trap name or number is invalid; otherwise, trap returns
True.
|
|
type [_all][_type | _path]
|
With no options, indicate how each name would be interpreted if used as a
|
|
name [name ...]
|
command name. If the _type flag is used,
type prints a phrase that is one of alias, keyword,
function, builtin, or file if name is an alias, shell reserved word,
function, builtin, or disk file, respectively. If the name is not found, then nothing is
printed, and an exit status of False is returned. If the
_path flag is used, type either returns the name of the disk file that would be executed if
name were specified as a command name, or nothing if
_type would not return file. If a command is hashed,
_path prints the hashed value, not necessarily the file that appears first in
PATH. If the _all flag is used, type prints all of the places that contain an executable named
name. This includes aliases and functions, if and only if the
_path flag is not also used. The table of hashed commands is
not consulted when using _all. type accepts _a, _t, and
_p in place of _all, _type, and _path, respectively. An argument of
— disables option checking for the rest of the arguments.
type returns True if any of the arguments are found,
False if none are found.
|
|
ulimit [_SHacdfmstpnuv [limit]]
|
ulimit provides control over the resources available to the shell and to
processes started by it, on systems that allow such control. The value of
limit can be a number in the unit specified for the resource, or the value
unlimited. The H and S options specify that the hard or soft limit is set for the given resource. A hard limit cannot
be increased once it is set; a soft limit may be increased up to the value of the
hard limit. If neither H nor S is specified, the command applies to the soft limit. If
limit is omitted, the current value of the soft limit of the resource is printed, unless the
H option is given. When more than one resource is specified, the
limit name and unit is printed before the value. Other options are interpreted as follows:
|
|
|
_a
|
All current limits are reported.
|
|
|
_c
|
The maximum size of core files created.
|
|
|
_d
|
The maximum size of a process's data segment.
|
|
|
_f
|
The maximum size of files created by the shell.
|
|
|
_m
|
The maximum resident set size.
|
|
|
_s
|
The maximum stack size.
|
|
|
_t
|
The maximum amount of cpu time in seconds.
|
|
|
_p
|
The pipe size in 512-byte blocks. (This may not be set.)
|
|
|
_n
|
The maximum number of open file descriptors. (Most
systems do not allow this value to be set, only displayed.)
|
|
|
_u
|
The maximum number of processes available to a single user.
|
|
|
_v
|
The maximum amount of virtual memory available to
the shell.
|