#Bash 的 stdbuf 命令

stdbuf OPTION... COMMAND

功能

使用指定的缓冲模式运行命令。

类型

可执行文件（/usr/bin/stdbuf），属于 coreutils。

参数

OPTION 选项：
- -i, --input=MODE - 指定标准输入的缓冲模式
- -o, --output=MODE - 指定标准输出的缓冲模式
- -e, --error=MODE - 指定标准错误的缓冲模式
- --help - 显示帮助
- --version - 显示版本
COMMAND - 要执行的命令

#缓冲模式

参考 setvbuf - 缓冲模式

0 - 无缓冲
L - 行缓冲（不能用于标准输入）
N - N 字节的全缓冲，支持 K（1024）、KB（1000）等后缀

#示例

$ stdbuf -o 0 cat /vat/log/xxx.log        # 使用无缓冲运行命令

#推荐阅读

#手册

STDBUF(1)                        User Commands                       STDBUF(1)

NAME
       stdbuf  - Run COMMAND, with modified buffering operations for its stan‐
       dard streams.

SYNOPSIS
       stdbuf OPTION... COMMAND

DESCRIPTION
       Run COMMAND,  with  modified  buffering  operations  for  its  standard
       streams.

       Mandatory  arguments  to  long  options are mandatory for short options
       too.

       -i, --input=MODE
              adjust standard input stream buffering

       -o, --output=MODE
              adjust standard output stream buffering

       -e, --error=MODE
              adjust standard error stream buffering

       --help display this help and exit

       --version
              output version information and exit

       If MODE is 'L' the corresponding stream will be  line  buffered.   This
       option is invalid with standard input.

       If MODE is '0' the corresponding stream will be unbuffered.

       Otherwise  MODE is a number which may be followed by one of the follow‐
       ing: KB 1000, K  1024,  MB  1000*1000,  M  1024*1024,  and  so  on  for
       G,T,P,E,Z,Y,R,Q.   Binary  prefixes can be used, too: KiB=K, MiB=M, and
       so on.  In this case the corresponding stream will  be  fully  buffered
       with the buffer size set to MODE bytes.

       NOTE:  If  COMMAND adjusts the buffering of its standard streams ('tee'
       does for example) then that  will  override  corresponding  changes  by
       'stdbuf'.   Also  some  filters  (like  'dd'  and 'cat' etc.) don't use
       streams for I/O, and are thus unaffected by 'stdbuf' settings.

   Exit status:
       125    if the stdbuf command itself fails

       126    if COMMAND is found but cannot be invoked

       127    if COMMAND cannot be found

       -      the exit status of COMMAND otherwise

EXAMPLES
       tail -f access.log | stdbuf -oL cut -d ' ' -f1 | uniq
       This will immediately display unique entries from access.log

BUGS
       On GLIBC  platforms,  specifying  a  buffer  size,  i.e.,  using  fully
       buffered mode will result in undefined operation.

AUTHOR
       Written by Padraig Brady.

REPORTING BUGS
       GNU coreutils online help: <https://www.gnu.org/software/coreutils/>
       Report any translation bugs to <https://translationproject.org/team/>

COPYRIGHT
       Copyright  ©  2023  Free Software Foundation, Inc.  License GPLv3+: GNU
       GPL version 3 or later <https://gnu.org/licenses/gpl.html>.
       This is free software: you are free  to  change  and  redistribute  it.
       There is NO WARRANTY, to the extent permitted by law.

SEE ALSO
       Full documentation <https://www.gnu.org/software/coreutils/stdbuf>
       or available locally via: info '(coreutils) stdbuf invocation'

GNU coreutils 9.4                 April 2024                         STDBUF(1)

#Bash 的 stdbuf 命令

#缓冲模式

#示例

#推荐阅读

#手册

显示