Linux fold命令

mytomorrow

( s) g0 ]+ ?4 \6 YLinux fold命令用于限制文件列宽。
) M9 `3 Y/ K0 l7 ~
% Z& q7 Q2 v3 Z6 H8 V+ {2 i4 xfold指令会从指定的文件里读取内容，将超过限定列宽的列加入增列字符后，输出到标准输出设备。若不指定任何文件名称，或是所给予的文件名为"-"，则fold指令会从标准输入设备读取数据。

& R/ b. A; d( E& w+ e- [
; A7 X8 ?' n1 r语法
# h1 l6 v8 }% ^+ ~# y# J7 ^+ l2 }
fold [-bs][-w<每列行数>][--help][--version][文件...]


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参数：

-b或--bytes 以Byte为单位计算列宽，而非采用行数编号为单位。
: Y3 j! d1 I& u" c7 g-s或--spaces 以空格字符作为换列点。
& b/ T9 N" L' N) S$ ?8 ~# U" _-w<每列行数>或--width<每列行数> 设置每列的最大行数。
--help 在线帮助。
0 O! T; J5 W  M/ l--version 显示版本信息。



2 N4 x( M5 H; M( A: N! y2 v实例
, Q0 \4 e. w4 n& ~$ T' {) x
将一个名为testfile 的文件的行折叠成宽度为30，可使用如下命令：

fold -w 30 testfile
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为了对比，先将testfile文件输出如下：
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& W3 [9 L4 ]$ Y3 ?+ k- H$ cat testfile #查看testfile 中的内容  
Linux networks are becoming more and more common, but
: J5 K3 I7 Z) h+ fsecurity is often an overlooked  
6 ]4 J0 i9 m! e) X* O) i) |6 Bissue. Unfortunately, in today’s environment all networks
are potential hacker targets,  
+ b5 S$ }4 _/ ^from top-secret military research networks to small home LANs.  
1 b( x: I. e' |7 G! q7 `8 R3 hLinux Network Security focuses on securing Linux in a
networked environment, where the  
$ [' D; o- O2 v" {: ]3 msecurity of the entire network needs to be considered
1 ?; Z; e- O% q4 u1 D9 {" t2 I8 Vrather than just isolated machines.  
It uses a mix of theory and practical techniques to
teach administrators how to install and  
use security applications, as well as how the
. i% O, x4 N3 g/ W. ^applications work and why they are necessary.

# j  E( b* Y' @: ?( `
然后使用fold命令折叠显示：
  ]1 r* Q- r" H$ ?$ S
$ fold -w 30 testfile #行折叠成宽度为30，显示testfile 文件  
Linux networks are becoming mo  
, P; s1 }" h4 ~' N- zre and more common, but securi  
* R. y7 O; ]* h) P6 A5 g" |ty is often an overlooked issu  
e. Unfortunately, in today’s  
environment all networks are  
3 `$ A2 C! j) N0 Q# P( G  P2 n! S) R* Wpotential hacker targets, from  
top-secret military research  
networks to small home LANs.  
Linux Network Security focuses  
+ b# A1 P, Z/ _* A7 L- `( don securing Linux in a networ  
. }! b. g! @' [0 x* V5 uked environment, where the sec  
& M+ g( p5 N3 X' B' D9 y) W$ Purity of the entire network ne  
eds to be considered rather th  
2 T: E) C, `& Q6 jan just isolated machines. It  
uses a mix of theory and pract  
ical techniques to teach admin  
istrators how to install and u  
se security applications, as w  
7 r2 _8 o! H/ Cell as how the applications wo  
rk and why they are necessary
% s9 r0 ?; c5 R$ t( W. I

AustCor1

Linux fold命令

yin123

Linux fold命令用于限制文件列宽

regngfpcb

fold指令会从指定的文件里读取内容，将超过限定列宽的列加入增列字符后，输出到标准输出设备