Ayer hice una instalación de Ubuntu 14. Accidentalmente, encontré el suspend
comando. Cuando lo ingreso en la línea de comando y presiono enter, la terminal se bloquea. Tampoco puedo interrumpirlo vía CTRL
+ C
, ni se está ejecutando un proceso con ese nombre que podría hacerlo kill
. Obviamente, esto no es un script, porque ambos which suspend
y whereis suspend
devuelven un resultado vacío:
void@wladiwostok ~ $ which suspend
void@wladiwostok ~ $ whereis suspend
suspend:
Así que supongo que suspend
debe ser algún tipo de comando "integrado" exit
o algo así. Sólo me pregunto,por curiosidad, ¿Qué hace?
No pude encontrar ninguna información en línea, porque la mayoría de las solicitudes de búsqueda me dieron información sobre cómosuspenderel ordenador.
Respuesta1
suspend
es un comando incorporado del shell:
¿Cómo saber eso?
Ejecute el tipo de comando antes de cualquier comando para saber qué es este comando:
$ type suspend
suspend is a shell builtin
Para obtener ayuda sobre los comandos integrados del shell, utilicehelp
help suspend
suspend: suspend [-f]
Suspend shell execution.
Suspend the execution of this shell until it receives a SIGCONT signal.
Unless forced, login shells cannot be suspended.
Options:
-f force the suspend, even if the shell is a login shell
Exit Status:
Returns success unless job control is not enabled or an error occurs.
Para enumerar todos los comandos integrados, simplemente ejecute help
el comando sin opciones.
help
la salida es:
job_spec [&] history [-c] [-d offset] [n] or hist>
(( expression )) if COMMANDS; then COMMANDS; [ elif C>
. filename [arguments] jobs [-lnprs] [jobspec ...] or jobs >
: kill [-s sigspec | -n signum | -sigs>
[ arg... ] let arg [arg ...]
[[ expression ]] local [option] name[=value] ...
alias [-p] [name[=value] ... ] logout [n]
bg [job_spec ...] mapfile [-n count] [-O origin] [-s c>
bind [-lpvsPVS] [-m keymap] [-f filen> popd [-n] [+N | -N]
break [n] printf [-v var] format [arguments]
builtin [shell-builtin [arg ...]] pushd [-n] [+N | -N | dir]
caller [expr] pwd [-LP]
case WORD in [PATTERN [| PATTERN]...)> read [-ers] [-a array] [-d delim] [->
cd [-L|[-P [-e]]] [dir] readarray [-n count] [-O origin] [-s>
command [-pVv] command [arg ...] readonly [-aAf] [name[=value] ...] o>
compgen [-abcdefgjksuv] [-o option] > return [n]
complete [-abcdefgjksuv] [-pr] [-DE] > select NAME [in WORDS ... ;] do COMM>
compopt [-o|+o option] [-DE] [name ..> set [-abefhkmnptuvxBCHP] [-o option->
continue [n] shift [n]
coproc [NAME] command [redirections] shopt [-pqsu] [-o] [optname ...]
declare [-aAfFgilrtux] [-p] [name[=va> source filename [arguments]
dirs [-clpv] [+N] [-N] suspend [-f]
disown [-h] [-ar] [jobspec ...] test [expr]
echo [-neE] [arg ...] time [-p] pipeline
enable [-a] [-dnps] [-f filename] [na> times
eval [arg ...] trap [-lp] [[arg] signal_spec ...]
exec [-cl] [-a name] [command [argume> true
exit [n] type [-afptP] name [name ...]
export [-fn] [name[=value] ...] or ex> typeset [-aAfFgilrtux] [-p] name[=va>
false ulimit [-SHacdefilmnpqrstuvx] [limit>
fc [-e ename] [-lnr] [first] [last] o> umask [-p] [-S] [mode]
fg [job_spec] unalias [-a] name [name ...]
for NAME [in WORDS ... ] ; do COMMAND> unset [-f] [-v] [name ...]
for (( exp1; exp2; exp3 )); do COMMAN> until COMMANDS; do COMMANDS; done
function name { COMMANDS ; } or name > variables - Names and meanings of so>
getopts optstring name [arg] wait [id]
hash [-lr] [-p pathname] [-dt] [name > while COMMANDS; do COMMANDS; done
help [-dms] [pattern ...] { COMMANDS ; }