Linux fold命令

mytomorrow

+ O2 h7 U3 [$ }" r1 u/ c5 dLinux fold命令用于限制文件列宽。
9 {, W3 I+ a+ ^& b
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。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。
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9 V9 p5 a0 F  p0 {3 d2 P5 ]2 D语法

fold [-bs][-w<每列行数>][--help][--version][文件...]



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。
-s或--spaces 以空格字符作为换列点。
-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。
--version 显示版本信息。
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实例
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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


  e0 c7 B+ m, ]  R1 l$ L为了对比，先将testfile文件输出如下：

# {( T8 X( c8 i8 e$ cat testfile #查看testfile 中的内容  
Linux networks are becoming more and more common, but
, }5 T% Y) F- Q1 L; E% u% v+ nsecurity is often an overlooked  
issue. Unfortunately, in today’s environment all networks
7 }4 E3 w' G9 L, N' e. p: y, Iare potential hacker targets,  
0 k  t4 J' A, v4 {from top-secret military research networks to small home LANs.  
3 ~* q3 ^7 g5 }  N" ?" ~4 ]Linux Network Security focuses on securing Linux in a
- y1 f; y* ~* Q6 j+ mnetworked environment, where the  
security of the entire network needs to be considered
rather than just isolated machines.  
; l' f/ R) s8 ~/ K' RIt uses a mix of theory and practical techniques to
teach administrators how to install and  
1 k2 e7 a, ]5 v' A1 nuse security applications, as well as how the
applications work and why they are necessary.
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然后使用fold命令折叠显示：

$ fold -w 30 testfile #行折叠成宽度为30，显示testfile 文件  
; k: ^1 F1 [* z9 J9 OLinux networks are becoming mo  
4 T& Q& c8 s0 Lre and more common, but securi  
: s' m$ v# [) N! @( Pty is often an overlooked issu  
$ j  f2 S1 f$ D7 Ae. Unfortunately, in today’s  
environment all networks are  
3 l/ F$ R9 D- I  r% ^" d' J  t- qpotential hacker targets, from  
, s. {& V; B+ R3 W/ d0 Ytop-secret military research  
networks to small home LANs.  
Linux Network Security focuses  
- H8 L* b; O& r! I) K+ _on securing Linux in a networ  
0 W- a5 E" C0 C' Xked environment, where the sec  
" n4 Z7 n7 |( t' E& A" aurity of the entire network ne  
. i, d0 G. L8 f4 j& i3 J$ {- Zeds to be considered rather th  
5 p' |* w$ S. ~$ R( I  H0 K7 c+ ]an just isolated machines. It  
uses a mix of theory and pract  
ical techniques to teach admin  
" y3 g6 V9 X/ [5 Histrators how to install and u  
se security applications, as w  
ell as how the applications wo  
rk and why they are necessary

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