亚洲av成人无遮挡网站在线观看,少妇性bbb搡bbb爽爽爽,亚洲av日韩精品久久久久久,兔费看少妇性l交大片免费,无码少妇一区二区三区

  免費(fèi)注冊 查看新帖 |

Chinaunix

  平臺 論壇 博客 文庫
最近訪問板塊 發(fā)新帖
查看: 915 | 回復(fù): 0
打印 上一主題 下一主題

linux中echo的用法 [復(fù)制鏈接]

論壇徽章:
0
跳轉(zhuǎn)到指定樓層
1 [收藏(0)] [報告]
發(fā)表于 2007-07-05 16:01 |只看該作者 |倒序?yàn)g覽
下面主要用例子說明用法(bash環(huán)境下測試)
1)echo顯示字符串
普通字符串可以在echo后直接輸入字符串,但這樣當(dāng)要輸出某些字符如\時會有問題(這種寫法的時候\是被當(dāng)作繼行符處理過濾掉的,要輸出一個\必須打\\,跟c語言printf輸出的要求相象),所以一般最好用´string´ 或"string"的格式,這樣即使是\也可以輸出,方便直觀。
#echo hello world
hello world
#echo hello\ world
hello world
#echo hello\\ world
hello\ world
#echo ´hello\\ world´ 或者: echo "hello\\ world"
hello\\ world
2)echo的轉(zhuǎn)義顯示: 加上-e參數(shù)
輸出多行
#echo -e ´hello\nworld´
hello
world
輸出ascii字符: echo -e \NNN   (NNN為ascii字符的八進(jìn)制碼號,不符合八進(jìn)制的將會按照字面意義進(jìn)行打印)
#echo -e ´\61 \62 \101 \141´
1 2 A a
更詳細(xì)的可以參看下面的參考資料,enjoy!
參考資料
info echo和man echo得到的信息:
File: coreutils.info, Node: echo invocation, Next: printf invocation, Up: Printing text
`echo´: Print a line of text
============================
`echo´ writes each given STRING to standard output, with a space
between each and a newline after the last one. Synopsis:
  echo [OPTION]... [STRING]...
The program accepts the following options. Also see *Note Common
options::.
`-n´
  Do not output the trailing newline.
`-e´
  Enable interpretation of the following backslash-escaped
  characters in each STRING:
  `\a´
    alert (bell)
  `\b´
    backspace
  `\c´
    suppress trailing newline
  `\f´
    form feed
  `\n´
    new line
  `\r´
    carriage return
  `\t´
    horizontal tab
  `\v´
    vertical tab
  `\\´
    backslash
  `\NNN´
    the character whose ASCII code is NNN (octal); if NNN is not
    a valid octal number, it is printed literally.
============================
echo - manual
ECHO(1)           FSF           ECHO(1)
NAME
  echo - display a line of text
SYNOPSIS
  echo [OPTION]... [STRING]...
DESCRIPTION
  NOTE: your shell may have its own version of echo which will supercede
  the version described here. Please refer to your shell´s documentation
  for details about the options it supports.
  Echo the STRING(s) to standard output.
  -n   do not output the trailing newline
  -e   enable interpretation of the backslash-escaped characters listed
    below
  -E   disable interpretation of those sequences in STRINGs
  --help display this help and exit
  --version
    output version information and exit
  Without -E, the following sequences are recognized and interpolated:
  \NNN the character whose ASCII code is NNN (octal)
  \\   backslash
  \a   alert (BEL)
  \b   backspace
  \c   suppress trailing newline
  \f   form feed
  \n   new line
  \r   carriage return
  \t   horizontal tab
  \v   vertical tab
AUTHOR
  Written by FIXME unknown.
REPORTING BUGS
  Report bugs to .
COPYRIGHT
  Copyright (C) 2002 Free Software Foundation, Inc.
  This is free software; see the source for copying conditions. There is
  NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR
  PURPOSE.
SEE ALSO
  The full documentation for echo is maintained as a Texinfo manual. If
  the info and echo programs are properly installed at your site, the
  command
    info echo
  should give you access to the complete manual.
GNU coreutils 4.5.3     February 2003         ECHO(1)


本文來自ChinaUnix博客,如果查看原文請點(diǎn):http://blog.chinaunix.net/u/13231/showart_334907.html
您需要登錄后才可以回帖 登錄 | 注冊

本版積分規(guī)則 發(fā)表回復(fù)

  

北京盛拓優(yōu)訊信息技術(shù)有限公司. 版權(quán)所有 京ICP備16024965號-6 北京市公安局海淀分局網(wǎng)監(jiān)中心備案編號:11010802020122 niuxiaotong@pcpop.com 17352615567
未成年舉報專區(qū)
中國互聯(lián)網(wǎng)協(xié)會會員  聯(lián)系我們:huangweiwei@itpub.net
感謝所有關(guān)心和支持過ChinaUnix的朋友們 轉(zhuǎn)載本站內(nèi)容請注明原作者名及出處

清除 Cookies - ChinaUnix - Archiver - WAP - TOP