☰

如何在 osx 上截断大文件？

tag-icon • tag-icon linux macos
如何在 osx 上截断大文件？

我有一个 500mb 的文件。我只想保留前 5mb。如何在 osx 上截断它，因为 'truncate' 命令不可用（并且无法通过 homebrew 安装）？

答案1

  1. 安装 truncate

    brew install truncate

  2. 将文件截断为 0 大小：

    truncate -s 0 your_filename

答案2

您可能应该尝试使用这个 - 空设备 /dev/null 充当黑洞，在类 Unix 操作系统下丢弃写入它的所有数据。您可以尝试按如下方式使用它：

cp /dev/null largefile.txt 或 cat /dev/null > largefile.txt

无论哪件事做对了，那它未来要做的就一定是正确的事情。

答案3

我知道这是一个老问题，但截至 2018 年 10 月，您可以通过 homebrew 安装它：

> brew info truncate
truncate: stable 0.9 (bottled), HEAD
Truncates a file to a given size
https://www.vanheusden.com/truncate/
/usr/local/Cellar/truncate/0.9 (4 files, 49.3KB) *
  Poured from bottle on 2018-10-31 at 14:54:21
From: https://github.com/Homebrew/homebrew-core/blob/master/Formula/truncate.rb
==> Options
--HEAD
    Install HEAD version
==> Analytics
install: 281 (30 days), 861 (90 days), 3,138 (365 days)
install_on_request: 283 (30 days), 862 (90 days), 3,124 (365 days)
build_error: 0 (30 days)

2022 年 9 月更新：

 ╰─ brew info coreutils
 ==> coreutils: stable 9.1 (bottled), HEAD
 GNU File, Shell, and Text utilities
 https://www.gnu.org/software/coreutils
 Conflicts with:
  aardvark_shell_utils (because both install `realpath` binaries)
  b2sum (because both install `b2sum` binaries)
  ganglia (because both install `gstat` binaries)
  gdu (because both install `gdu` binaries)
  idutils (because both install `gid` and `gid.1`)
  md5sha1sum (because both install `md5sum` and `sha1sum` binaries)
  truncate (because both install `truncate` binaries)
  uutils-coreutils (because coreutils and uutils-coreutils install the same binaries)
 Not installed
 From: https://github.com/Homebrew/homebrew-core/blob/HEAD/Formula/coreutils.rb
 License: GPL-3.0-or-later
 ==> Dependencies
 Required: gmp ✘
 ==> Options
    --HEAD
    Install HEAD version
 ==> Caveats
 Commands also provided by macOS and the commands dir, dircolors, vdir have been installed with the prefix "g".
 If you need to use these commands with their normal names, you can add a "gnubin" directory to your PATH with:
  PATH="/opt/homebrew/opt/coreutils/libexec/gnubin:$PATH"
 ==> Analytics
 install: 86,771 (30 days), 265,204 (90 days), 1,257,918 (365 days)
 install-on-request: 62,729 (30 days), 190,281 (90 days), 885,118 (365 days)
 build-error: 132 (30 days)

答案4

: > filename

冒号表示真且不产生任何输出，因此没有任何内容被重定向到文件 - 从而覆盖其所有内容。

相关内容