UNIX操作系统基础.docx

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1、Linux操作系统基础教程提到Linux操作系统，就不能不提UNIX和GNU。UNIX是由AT&T Bell 实验室于1969年开发的多用户、多任务操作系统，是目前广泛使用的商业操作系统。而GNU则开始于1984年，Richard Stallman发起的 GNU计划，目的是为了创建一套完全自由的操作系统（GNU宣 言）。GNU是“GNUs Not Unix”的递归缩写。（通用公共许可 GNU General Public License，GPL，反版权copyleft, 自由软件基金会Free Software Foundation, FSF）。1991年，Linus Torvalds编写了与

2、UNIX兼容的LINUX操作系统并在GPL条款下发布。1992年， Linux与其他GNU软件结合，产生了完全自由的操作系统，所以Linux操作系统又被称为 “GNU/Linux”。三大主流shell查看文件/etc/shell，可列出操作系统所包含的shellBourne shell也称sh，是Version 7 Unix默认的Unix Shell。Bourne Again Shell 多数Linux操作系统的默认shell，是Bourne shell（UC Berleley）的扩展，是Bourne again/ Born again shell的双关语，1987年由Brian Fox创造。

3、C shell，TC shell模仿C的语法，开发与BSD系统，脱胎于第六版UNIX的/bin/sh，也是 Bourne shell的前身，加入了alias, command history等功能。Korn shell是第一个UNIX shell，它完全向上兼容Bourne shell并包含了许多C shell的特性。查看用户的默认shell，请查看文件/etc/passwd每个进程都有一个进程号pid，可用pstree或者ps ef命令查看1. 常用Linux命令（1） uname（2） ls（3） ps（4） date（5） who（6） pwd（7） mkdir（8） rmdir（9）

4、rm（10） touch（11） id（12） group（13） su（14） which（15） where2. C Shell1. shbang line#!/bin/csh 或者 #!/bin/tcsh2. comments# this is comment line3. wildcards4.5. local variablesset variable=value set tom=”tom”6. global variables setenv variable value setenv tom tom7. extract the variable value echo $variab

5、le_name echo $nameecho $PRINTER8. user inputecho “what is your name?” set name = $, =, , , =, , , =, , =14. conditional statements15. loops16. functions function_name() block of codefunction function_name block of code6. regular expression and pattern matching正则表达式与模式匹配1. regular expressiondefinitio

6、n: a regular expression is just a pattern of characters used to match the same characters in a search.Hi Tom,I think I failed my anatomy test yesterday. I had a terrible stomachache. I ate too many fried green tomatoes. Anyway, Tom, I need your help. Id like to make the test up tomorrow, but dont kn

7、ow where to begin studying. Do you think you could help me? After work, about 7 PM, come to my place and Ill treat you to pizza in return for your help. Thanks.Your Pal, guyphantomif we want to substitute “Tom” or “tom” in the text to “admin”, how?vi里面寻找包含”tom”的行：/tom/，如果只是简单的寻找，一方面无法找到Tom，另一方面还会找到s

8、tomachache、tommorrow以及tomatoes等。因此需要比较复杂的正则表达式的应用。:1,$s/admin/g即可完成替代 其中1,$表示从第一行到最后一行 s表示取代（substitute） Tt表示字母”T”或者”t”的其中一个 表示一个单词的结束，这里不一定是同一个单词 /g表示全局取代Beginning of line anchor/love/Matches all lines beginning with love$End of line anchor/love$/Matches all lines ending with love.Matches one chara

9、cter/l.e/Matches lines containing an l,Followed by two characters*Matches zero or more ofthe preceding/ *love/Matches lines with zero or more spaces,followed by the pattern love Matches one in the set/Llove/Matches line containing love or Lovex-yMatches one characterwithin range from x to y/A-Zove/M

10、atches letters from A through Zfollowed by ove Matches one characternot in the set/A-Z/Matches any character not in the rangebetween A and ZUsed to escape a meacharacter/love./Matches lines containing love, followedby a literal period; normally the period matches a single any characterBeginning of w

11、ord anchor/End-of-word anchor/love/Matches lines containing a word that2. metacharacter元字符ends with love (supported by vi andgrep)(.)Tags match characters to be used/(love)able1er/May use up to nine tags, starting with the first tag at the leftmost part of thepatternxm or xm, orxm,no5,10Matches if l

12、ine contains between 5 to 10 consecutive occurrence of the letter o (supported by vi and grep)I had a lovely time on our little picnic. Lovers were all around us. It is springtime. Oh love, how much I adore you. Do you know the extent of my love? Oh, by the way, I think I lost my gloves somewhere ou

13、t in that field of clover. Did you see them? I can only hope love is forever. I live for you. Its hard to get back in the groove.example：/love/love$/l.ve/ 中，dot(.)匹配除了换行符之外的任意字符，如live/love/leve/lave/o*ve/ 中，asterisk(*)匹配0个到多个前一个字符o，包括ve/ove/oove/Llove/匹配love/Love/ovea-z/匹配ovea/oveb/ovez/oveA-Za-z0-9

14、/匹配与ove紧跟的字符不是大写、小写字母和数字，例如”ove “(空格)Christian Scott lives here and will put on a Christmas party. There are around 30 to 35 people invited.They are:TomDanRhonda Savage Nicky and KimberlySteve, Suzanne, Ginger and Larry.3. 更为复杂的元字符/A-Z.$/匹配大写字母开始，长度为3个字符的行/A-Za-z *30-5/大写字母开始，紧跟0个或多个小写字母或空格，再紧跟数字3和0

15、-5之间数字的行/ *A-Za-za-z$/匹配0个到多个空格开始，后面紧跟一个大写字母和两个小写字母的行/a-z*./匹配包含0-多个小写字母，后面紧跟句号的行/A-Za-z*,A-Za-z*$/呢？4. more regular expression$ cat textfileUnusual occurrences happened at the fair.Patty won fourth place in the 50 yard dash square and fair. Occurences like this are rare.The winning ticket is 55222.

16、The ticket I got is 54333 and Dee got 55544.Guy fell down while running around the south bend in his last event. 在每一行查找单词fourth 查找以f开始的单词，后面紧跟0-多个字符，最后是”th”的字符串的行 将所有occurence 和 Occurence 修改为occurrence和Occurrence:1,$s/(Ooccur/)ence/1rence/g 颠换短句”fair and square”中的单词fair 和 square:1,$s/(fair) and (squ

17、are)/2 and 1/g 查找包含连续两个5，紧跟3个2，后面是句号:1,$/5223./5. grep family继续巩固正则表达式：来源于ex编辑器grep是常用的查找pattern的命令ex编辑器:/RE/p打印包含pattern的第一行:g/RE/p打印所有包含pattern的行工作模式在一个或多个文件中查找多个字符模式，如果存在空格，模式必须用引号用法grep word filename1 filename2如在/etc/passwd中查找admin这个用户：grep admin /etc/passwd常用于管道，例如ps ef | grep bash grep选项列表Opti

18、onsWhat it does-b找到匹配的位置在行前输入block number-c输出匹配行的数目，而不输出结果-h不显示文件名-i不考虑匹配字母的大小写-l列出具有匹配行的文件名称，用分行符分割-n在前面输出行号，紧跟该行内容-sSilently没有输出，除非有错误产生，用来检查退出状态，找到返回0，找不到模式退出状态为1，找不到文件报错退出状态为2；可用echo $?检查状态-vInverts，仅仅输出不匹配的行-w查找表达式作为一个单词，把它视作内部6. examples grep NW datafile grep NW d* grep n datafile grep 4$ data

19、file grep TB Savage datafile grep 5. datafile grep .5 datafile grep we datafile grep 0-9 datafile grep A-ZA-Z A-Z datafile grep ss* datafile grep a-z5,9 datafile grep north datafile grep datafile grep a-z.*n datafile grep n south datafile grep i pat datafile grep v Suan Chin datafile grep v Suan Chi

20、n datafile tempfile mv temp datafile grep l SE * grep c west datafile grep w north datafile ls l | grep d+matches one or more of the preceding charactera-z+ove?matches zero or one of the preceding characterlo?vea|bmatches either a or blove|hate()group characterslove(able|ly) (ov)+ rpm qa | grep http

21、 metacharacteregrepegrep + fileprints lines beginning with one or more spaces egrep * fileprints lines beginning with zero or more spacesegrep (Tom|Dan) Savage prints lines containing Tom Savage or Dan Savage egrep (ab)+ fileprints lines with one or more occurrences of abegrep X0-9?prints lines begi

22、nning with X followed by 0-1 single digitfgrep: fixed grep, does not recognize any regular expression metacharacters as being special. grep Rrecursively descend a directory treergreplinux GNU grepgrep pattern filename 基本方式grep G pattern filename 基本方式grep E pattern filename 扩展RE元字符grep F pattern file

23、name 无RE元字符，同fgrep grep P pattern filename 理解为Perl-REw表示a-zA-Z0-9_W表示a-zA-Z0-9_b表示边界，例如bloveb匹配单词love egrep NW|EA datafile grep E NW|EA datafile grep NW|EA datafile grep NW|EA datafile egrep 3+ datafile grep E 3+ datafile grep 3+ datafile egrep 2.?0-9 datafile grep E 2.?0-9 datafile grep 2.?0-9 datafilegrep V显示版本号grep -2 显示pattern的前后两行grep C 2 前后两行 grep A 2 后面两行 grep B 2 后面两行