为什么没有 disown 或其他 Ubuntu 命令的手册页？

Question

phatez@phatez-laptop:~$ help

GNU bash, version 4.3.46(1)-release (x86_64-pc-linux-gnu)
These shell commands are defined internally.  Type `help' to see this list.
Type `help name' to find out more about the function `name'.
Use `info bash' to find out more about the shell in general.
Use `man -k' or `info' to find out more about commands not in this list.

A star (*) next to a name means that the command is disabled.

 job_spec [&]                                             history [-c] [-d offset] [n] or history -anrw [filena>
 (( expression ))                                         if COMMANDS; then COMMANDS; [ elif COMMANDS; then COM>
 . filename [arguments]                                   jobs [-lnprs] [jobspec ...] or jobs -x command [args]>
 :                                                        kill [-s sigspec | -n signum | -sigspec] pid | jobspe>
 [ arg... ]                                               let arg [arg ...]
 [[ expression ]]                                         local [option] name[=value] ...
 alias [-p] [name[=value] ... ]                           logout [n]
 bg [job_spec ...]                                        mapfile [-n count] [-O origin] [-s count] [-t] [-u fd>
 bind [-lpsvPSVX] [-m keymap] [-f filename] [-q name] [>  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]...) COMMANDS ;;]... >  read [-ers] [-a array] [-d delim] [-i text] [-n nchar>
 cd [-L|[-P [-e]] [-@]] [dir]                             readarray [-n count] [-O origin] [-s count] [-t] [-u >
 command [-pVv] command [arg ...]                         readonly [-aAf] [name[=value] ...] or readonly -p
 compgen [-abcdefgjksuv] [-o option]  [-A action] [-G g>  return [n]
 complete [-abcdefgjksuv] [-pr] [-DE] [-o option] [-A a>  select NAME [in WORDS ... ;] do COMMANDS; done
 compopt [-o|+o option] [-DE] [name ...]                  set [-abefhkmnptuvxBCHP] [-o option-name] [--] [arg .>
 continue [n]                                             shift [n]
 coproc [NAME] command [redirections]                     shopt [-pqsu] [-o] [optname ...]
 declare [-aAfFgilnrtux] [-p] [name[=value] ...]          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] [name ...]             times
 eval [arg ...]                                           trap [-lp] [[arg] signal_spec ...]
 exec [-cl] [-a name] [command [arguments ...]] [redire>  true
 exit [n]                                                 type [-afptP] name [name ...]
 export [-fn] [name[=value] ...] or export -p             typeset [-aAfFgilrtux] [-p] name[=value] ...
 false                                                    ulimit [-SHabcdefilmnpqrstuvxT] [limit]
 fc [-e ename] [-lnr] [first] [last] or fc -s [pat=rep]>  umask [-p] [-S] [mode]
 fg [job_spec]                                            unalias [-a] name [name ...]
 for NAME [in WORDS ... ] ; do COMMANDS; done             unset [-f] [-v] [-n] [name ...]
 for (( exp1; exp2; exp3 )); do COMMANDS; done            until COMMANDS; do COMMANDS; done
 function name { COMMANDS ; } or name () { COMMANDS ; }>   variables - Names and meanings of some shell variable>
 getopts optstring name [arg]                             wait [-n] [id ...]
 hash [-lr] [-p pathname] [-dt] [name ...]                while COMMANDS; do COMMANDS; done
 help [-dms] [pattern ...]                                { COMMANDS ; }


phatez@phatez-laptop:~$ man ulimit


phatez@phatez-laptop:~$ man disown

No manual entry for disown


phatez@phatez-laptop:~$ 

Answer 1

disown是一个内置的bash。所以man bash会显示......

否认 [-ar] [-h] [jobspec ...]

如果没有选项，请从活动作业表中删除每个作业规范。如果 jobspec 不存在，并且既没有提供 -a 也没有提供 -r 选项，则使用当前作业。如果给出了 -h 选项，则不会从表中删除每个作业规范，而是将其标记为在 shell 收到 SIGHUP 时不会将 SIGHUP 发送到作业。如果没有提供jobspec， -a 选项表示删除或标记所有作业；没有工作的 -r 选项？spec 参数将操作限制为正在运行的作业。除非作业规范未指定有效作业，否则返回值为 0。

还有很多。这是一个列表。

列出帮助类型

help disown

或其他 ubuntu 命令？

所有 Ubuntu（Linux 更精确）命令都有一个手册页。

ulimit 确实有手册页。

ULIMIT(3) Linux 程序员手册 ULIMIT(3)

NAME ulimit - 获取和设置用户限制

概要

  #include <ulimit.h>

  long ulimit(int cmd, long newlimit);

但你可能是指参数？

2种方式：

$help ulimit
ulimit: ulimit [-SHabcdefilmnpqrstuvxT] [limit]
    Modify shell resource limits.

    Provides control over the resources available to the shell and processes
    it creates, on systems that allow such control.

    Options:
      -S    use the `soft' resource limit
      -H    use the `hard' resource limit
      -a    all current limits are reported
      -b    the socket buffer size
      -c    the maximum size of core files created

 ...

$ ulimit -a
core file size          (blocks, -c) 0
data seg size           (kbytes, -d) unlimited
scheduling priority             (-e) 0
file size               (blocks, -f) unlimited
pending signals                 (-i) 46690
max locked memory       (kbytes, -l) 64
max memory size         (kbytes, -m) unlimited
open files                      (-n) 1024
pipe size            (512 bytes, -p) 8
POSIX message queues     (bytes, -q) 819200
real-time priority              (-r) 0
stack size              (kbytes, -s) 8192
cpu time               (seconds, -t) unlimited
max user processes              (-u) 46690
virtual memory          (kbytes, -v) unlimited
file locks                      (-x) unlimited

Answer 2

当您键入时，help您会看到内置于 bash 中的命令。要查看这些命令的帮助，请键入help <command>：

help ulimit
help disown

当您使用man（manual 的缩写）时，您会显示不属于 bash 的二进制程序的帮助。您注意到，ulimit如果您键入，您将获得帮助man ulimit。但是，ulimit 的手册不适用于 bash 命令。当您键入时，man ulimit您将获得 C 编程头文件的手册ulimit.h，这是完全不同的。