Chinaunix首页 | 论坛 | 博客
  • 博客访问: 319722
  • 博文数量: 240
  • 博客积分: 0
  • 博客等级: 民兵
  • 技术积分: 50
  • 用 户 组: 普通用户
  • 注册时间: 2016-08-04 18:14
文章分类

全部博文(240)

文章存档

2017年(8)

2014年(4)

2013年(15)

2012年(4)

2011年(14)

2010年(55)

2009年(140)

我的朋友

分类: LINUX

2009-06-27 03:34:42

 

# 统计各行域的个数

 cat /etc/hosts|awk '{print NF}'

 # 统计行数 (类似于 "wc -l")

 awk 'END{print NR}'

 # 打印匹配 sda 的行的第五个域

 df -h|awk '/sda/ {print $5}'
 df -h|awk '!/sda/ {print $5}'
 
 # 将同时包含WEB和ztgame的第一个域行打印出来

 awk '/WEB/ && /ztgame/ {print $1}' /etc/hosts

 # 打印匹配 sda 或 sdb 的行的第五个域

 df -h|gawk '/sda|sdb/ {print $5}'

 # 将第一列是 /dev/sda1 的行的第五个域打印出来

 df -h|awk '$1 == "/dev/sda1" {print $5}'
 df -h|awk '$1 != "/dev/sda1" {print $5}'

 # 将第五个域符合条件的(80%-99%)打印出来

 df -h|awk '$5 ~ /^[8-9][0-9]/ {print $1,"nearly full!",$5}'
 df -h|awk '$5 !~ /^[8-9][0-9]/ {print $1,"nearly full!",$5}'

 # 打印匹配 sda 的行,如果第一个域是 sda1 则打印yes,否则打印no

 df -h|awk 'sda {if($1=="sda1") {print "yes"} else {print "no"}}'

 # 取出磁盘利用率,如果磁盘使用超过 80% 则打印磁盘满

 df -h|grep sda1|awk -F'%' {'print $1'}|awk '{if($5>80) {print "Disk full!"} else {print "Healthy!"}}'

 # 查找所有.log 的文件并且只输出文件名

 find . -name *.log|awk -F/ '{print $NF}'|sort|uniq

 # 将所有行的各个域反响输出(注意与rev 不同,rev 是按字符反序,而这个是按域反序)

 awk '{for (i=NF; i>0; i--) printf("%s ",$i);print ""}'



输出所有的奇数行/偶数行
cat filename |awk '{if (NR%2!=0) {print $0 "-1"} }'
cat filename |awk '{if (NR%2==0) {print $0 "-2"} }'

在文件奇数行后加 1 ,偶数行后加 2:
cat filename |awk '{if (NR%2!=0) {print $0 "-1"} else {print $0 "-2"} }'

 

全文:

HANDY ONE-LINE SCRIPTS FOR AWK 30 April 2008
Compiled by Eric Pement - eric [at] pement.org version 0.27

Latest version of this file (in English) is usually at:
   

This file will also be available in other languages:
   Chinese -

USAGE:

   Unix: awk '/pattern/ {print "$1"}' # standard Unix shells

DOS/Win: awk '/pattern/ {print "$1"}' # compiled with DJGPP, Cygwin

         awk "/pattern/ {print \"$1\"}" # GnuWin32, UnxUtils, Mingw


Note that the DJGPP compilation (for DOS or Windows-32) permits an awk
script to follow Unix quoting syntax '/like/ {"this"}'. HOWEVER, if the
command interpreter is CMD.EXE or COMMAND.COM, single quotes will not
protect the redirection arrows (<, >) nor do they protect pipes (|).
These are special symbols which require "double quotes" to protect them
from interpretation as operating system directives. If the command
interpreter is bash, ksh or another Unix shell, then single and double
quotes will follow the standard Unix usage.

Users of MS-DOS or Microsoft Windows must remember that the percent
sign (%) is used to indicate environment variables, so this symbol must
be doubled (%%) to yield a single percent sign visible to awk.

If a script will not need to be quoted in Unix, DOS, or CMD, then I
normally omit the quote marks. If an example is peculiar to GNU awk,
the command 'gawk' will be used. Please notify me if you find errors or
new commands to add to this list (total length under 65 characters). I
usually try to put the shortest script first. To conserve space, I
normally use '1' instead of '{print}' to print each line. Either one
will work.

FILE SPACING:

 # double space a file

 awk '1;{print ""}'
 awk 'BEGIN{ORS="\n\n"};1'

 # double space a file which already has blank lines in it. Output file

 # should contain no more than one blank line between lines of text.

 # NOTE: On Unix systems, DOS lines which have only CRLF (\r\n) are

 # often treated as non-blank, and thus 'NF' alone will return TRUE.

 awk 'NF{print $0 "\n"}'

 # triple space a file

 awk '1;{print "\n"}'

NUMBERING AND CALCULATIONS:

 # precede each line by its line number FOR THAT FILE (left alignment).

 # Using a tab (\t) instead of space will preserve margins.

 awk '{print FNR "\t" $0}' files*

 # precede each line by its line number FOR ALL FILES TOGETHER, with tab.

 awk '{print NR "\t" $0}' files*

 # number each line of a file (number on left, right-aligned)

 # Double the percent signs if typing from the DOS command prompt.

 awk '{printf("%5d : %s\n", NR,$0)}'

 # number each line of file, but only print numbers if line is not blank

 # Remember caveats about Unix treatment of \r (mentioned above)

 awk 'NF{$0=++a " :" $0};1'
 awk '{print (NF? ++a " :" :"") $0}'

 # count lines (emulates "wc -l")

 awk 'END{print NR}'

 # print the sums of the fields of every line

 awk '{s=0; for (i=1; i<=NF; i++) s=s+$i; print s}'

 # add all fields in all lines and print the sum

 awk '{for (i=1; i<=NF; i++) s=s+$i}; END{print s}'

 # print every line after replacing each field with its absolute value

 awk '{for (i=1; i<=NF; i++) if ($i < 0) $i = -$i; print }'
 awk '{for (i=1; i<=NF; i++) $i = ($i < 0) ? -$i : $i; print }'

 # print the total number of fields ("words") in all lines

 awk '{ total = total + NF }; END {print total}' file

 # print the total number of lines that contain "Beth"

 awk '/Beth/{n++}; END {print n+0}' file

 # print the largest first field and the line that contains it

 # Intended for finding the longest string in field #1

 awk '$1 > max {max=$1; maxline=$0}; END{ print max, maxline}'

 # print the number of fields in each line, followed by the line

 awk '{ print NF ":" $0 } '

 # print the last field of each line

 awk '{ print $NF }'

 # print the last field of the last line

 awk '{ field = $NF }; END{ print field }'

 # print every line with more than 4 fields

 awk 'NF > 4'

 # print every line where the value of the last field is > 4

 awk '$NF > 4'

STRING CREATION:

 # create a string of a specific length (e.g., generate 513 spaces)

 awk 'BEGIN{while (a++<513) s=s " "; print s}'

 # insert a string of specific length at a certain character position

 # Example: insert 49 spaces after column #6 of each input line.

 gawk --re-interval 'BEGIN{while(a++<49)s=s " "};{sub(/^.{6}/,"&" s)};1'

ARRAY CREATION:

 # These next 2 entries are not one-line scripts, but the technique

 # is so handy that it merits inclusion here.

 
 # create an array named "month", indexed by numbers, so that month[1]

 # is 'Jan', month[2] is 'Feb', month[3] is 'Mar' and so on.

 split("Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec", month, " ")

 # create an array named "mdigit", indexed by strings, so that

 # mdigit["Jan"] is 1, mdigit["Feb"] is 2, etc. Requires "month" array

 for (i=1; i<=12; i++) mdigit[month[i]] = i

TEXT CONVERSION AND SUBSTITUTION:

 # IN UNIX ENVIRONMENT: convert DOS newlines (CR/LF) to Unix format

 awk '{sub(/\r$/,"")};1' # assumes EACH line ends with Ctrl-M


 # IN UNIX ENVIRONMENT: convert Unix newlines (LF) to DOS format

 awk '{sub(/$/,"\r")};1'

 # IN DOS ENVIRONMENT: convert Unix newlines (LF) to DOS format

 awk 1

 # IN DOS ENVIRONMENT: convert DOS newlines (CR/LF) to Unix format

 # Cannot be done with DOS versions of awk, other than gawk:

 gawk -v BINMODE="w" '1' infile >outfile

 # Use "tr" instead.

 tr -d \r outfile # GNU tr version 1.22 or higher


 # delete leading whitespace (spaces, tabs) from front of each line

 # aligns all text flush left

 awk '{sub(/^[ \t]+/, "")};1'

 # delete trailing whitespace (spaces, tabs) from end of each line

 awk '{sub(/[ \t]+$/, "")};1'

 # delete BOTH leading and trailing whitespace from each line

 awk '{gsub(/^[ \t]+|[ \t]+$/,"")};1'
 awk '{$1=$1};1' # also removes extra space between fields


 # insert 5 blank spaces at beginning of each line (make page offset)

 awk '{sub(/^/, " ")};1'

 # align all text flush right on a 79-column width

 awk '{printf "%79s\n", $0}' file*

 # center all text on a 79-character width

 awk '{l=length();s=int((79-l)/2); printf "%"(s+l)"s\n",$0}' file*

 # substitute (find and replace) "foo" with "bar" on each line

 awk '{sub(/foo/,"bar")}; 1' # replace only 1st instance

 gawk '{$0=gensub(/foo/,"bar",4)}; 1' # replace only 4th instance

 awk '{gsub(/foo/,"bar")}; 1' # replace ALL instances in a line


 # substitute "foo" with "bar" ONLY for lines which contain "baz"

 awk '/baz/{gsub(/foo/, "bar")}; 1'

 # substitute "foo" with "bar" EXCEPT for lines which contain "baz"

 awk '!/baz/{gsub(/foo/, "bar")}; 1'

 # change "scarlet" or "ruby" or "puce" to "red"

 awk '{gsub(/scarlet|ruby|puce/, "red")}; 1'

 # reverse order of lines (emulates "tac")

 awk '{a[i++]=$0} END {for (j=i-1; j>=0;) print a[j--] }' file*

 # if a line ends with a backslash, append the next line to it (fails if

 # there are multiple lines ending with backslash...)

 awk '/\\$/ {sub(/\\$/,""); getline t; print $0 t; next}; 1' file*

 # print and sort the login names of all users

 awk -F ":" '{print $1 | "sort" }' /etc/passwd

 # print the first 2 fields, in opposite order, of every line

 awk '{print $2, $1}' file

 # switch the first 2 fields of every line

 awk '{temp = $1; $1 = $2; $2 = temp}' file

 # print every line, deleting the second field of that line

 awk '{ $2 = ""; print }'

 # print in reverse order the fields of every line

 awk '{for (i=NF; i>0; i--) printf("%s ",$i);print ""}' file

 # concatenate every 5 lines of input, using a comma separator

 # between fields

 awk 'ORS=NR%5?",":"\n"' file

SELECTIVE PRINTING OF CERTAIN LINES:

 # print first 10 lines of file (emulates behavior of "head")

 awk 'NR < 11'

 # print first line of file (emulates "head -1")

 awk 'NR>1{exit};1'

  # print the last 2 lines of a file (emulates "tail -2")

 awk '{y=x "\n" $0; x=$0};END{print y}'

 # print the last line of a file (emulates "tail -1")

 awk 'END{print}'

 # print only lines which match regular expression (emulates "grep")

 awk '/regex/'

 # print only lines which do NOT match regex (emulates "grep -v")

 awk '!/regex/'

 # print any line where field #5 is equal to "abc123"

 awk '$5 == "abc123"'

 # print only those lines where field #5 is NOT equal to "abc123"

 # This will also print lines which have less than 5 fields.

 awk '$5 != "abc123"'
 awk '!($5 == "abc123")'

 # matching a field against a regular expression

 awk '$7 ~ /^[a-f]/' # print line if field #7 matches regex

 awk '$7 !~ /^[a-f]/' # print line if field #7 does NOT match regex


 # print the line immediately before a regex, but not the line

 # containing the regex

 awk '/regex/{print x};{x=$0}'
 awk '/regex/{print (NR==1 ? "match on line 1" : x)};{x=$0}'

 # print the line immediately after a regex, but not the line

 # containing the regex

 awk '/regex/{getline;print}'

 # grep for AAA and BBB and CCC (in any order on the same line)

 awk '/AAA/ && /BBB/ && /CCC/'

 # grep for AAA and BBB and CCC (in that order)

 awk '/AAA.*BBB.*CCC/'

 # print only lines of 65 characters or longer

 awk 'length > 64'

 # print only lines of less than 65 characters

 awk 'length < 64'

 # print section of file from regular expression to end of file

 awk '/regex/,0'
 awk '/regex/,EOF'

 # print section of file based on line numbers (lines 8-12, inclusive)

 awk 'NR==8,NR==12'

 # print line number 52

 awk 'NR==52'
 awk 'NR==52 {print;exit}' # more efficient on large files


 # print section of file between two regular expressions (inclusive)

 awk '/Iowa/,/Montana/' # case sensitive


SELECTIVE DELETION OF CERTAIN LINES:

 # delete ALL blank lines from a file (same as "grep '.' ")

 awk NF
 awk '/./'

 # remove duplicate, consecutive lines (emulates "uniq")

 awk 'a !~ $0; {a=$0}'

 # remove duplicate, nonconsecutive lines

 awk '!a[$0]++' # most concise script

 awk '!($0 in a){a[$0];print}' # most efficient script


CREDITS AND THANKS:

Special thanks to the late Peter S. Tillier (U.K.) for helping me with
the first release of this FAQ file, and to Daniel Jana, Yisu Dong, and
others for their suggestions and corrections.

For additional syntax instructions, including the way to apply editing
commands from a disk file instead of the command line, consult:

  "sed & awk, 2nd Edition," by Dale Dougherty and Arnold Robbins
  (O'Reilly, 1997)

  "UNIX Text Processing," by Dale Dougherty and Tim O'Reilly (Hayden
  Books, 1987)

  "GAWK: Effective awk Programming," 3d edition, by Arnold D. Robbins
  (O'Reilly, 2003) or at

To fully exploit the power of awk, one must understand "regular
expressions." For detailed discussion of regular expressions, see
"Mastering Regular Expressions, 3d edition" by Jeffrey Friedl (O'Reilly,
2006).

The info and manual ("man") pages on Unix systems may be helpful (try
"man awk", "man nawk", "man gawk", "man regexp", or the section on
regular expressions in "man ed").

USE OF '\t' IN awk SCRIPTS: For clarity in documentation, I have used
'\t' to indicate a tab character (0x09) in the scripts. All versions of
awk should recognize this abbreviation.

#---end of file---


阅读(636) | 评论(0) | 转发(0) |
0

上一篇:SED 文档翻译

下一篇:Linux sync 命令

给主人留下些什么吧!~~