AIX下AWK语言的操作符

awk操作符
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= += *= / = %= ^ = 赋值操作符
？条件表达操作符
|| && ！并，与，非
< <= == ！= >> 关系操作符
+ - * / % ^ 算术操作符
+ + -- 前缀和后缀
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1.设置输入域到域变量名
awk "{name=$1;color=$4; if（color ~/Yello/）print name" " is color "color}" grade.txt
P.Bunny is color Yello

2.赋值比较，通常在BEGIN部分赋值
a.在BEGIN中给变量名赋值
awk "BEGIN {BASELINE="27 "} {if（$6<BASELINE） print $0}" grade.txt
J.Lulu 06/99 48317 green 9 24 26
J.Troll 07/99 4842 Brown-3 12 26 26
b.在关系操作中使用实际数值
awk "{if（$6 < 27） print $0}" grade.txt
J.Lulu 06/99 48317 green 9 24 26
J.Troll 07/99 4842 Brown-3 12 26 26

3.修改数值域取值
awk "{if（$1=="M.Tansley"） $5=$6-1; print $1, $6, $5, $7}" grade.txt
M.Tansley 40 39 44
J.Lulu 24 9 26
P.Bunny 35 12 28
J.Troll 26 12 26
L.Tansley 30 12 28

4.修改文本域
awk "{if（$1=="J.Troll"）（$1="J.Troll.L"）;print $1}" grade.txt
M.Tansley
J.Lulu
P.Bunny
J.Troll.L
L.Tansley

5.只显示修改记录
awk "{if（ $1 == "J.Troll" ） {$1="J.Troll.L"; print $1}" grade.txt
awk: Syntax error
at line 1 of program << {if（ $1 == "J.Troll" ... >>
context is
{if（ $1 == "J.Troll" ） {$1="J.Troll.L"; print >>> $1} <<<
1 extra {
awk: illegal statement
at line 1 of program << {if（ $1 == "J.Troll" ... >>
错误原因：少了一个“}”结束
awk "{if（ $1 == "J.Troll" ） {$1="J.Troll.L"; print $1}}" grade.txt
J.Troll.L

6.创建新的域
awk "BEGIN{ print "Name Difference"}
{if（$6 < $7） {$8=$7-$6; print $1,$8}}" grade.txt
Name Difference
M.Tansley 4
J.Lulu 2

7.统计数据
awk "（tot += $6）; END{print "Club student total points:" tot}" grade.txt
M.Tansley 05/99 48311 Green 8 40 44
J.Lulu 06/99 48317 green 9 24 26
P.Bunny 02/99 48 Yello 12 35 28
J.Troll 07/99 4842 Brown-3 12 26 26
L.Tansley 05/99 4712 Brown-2 12 30 28
Club student total points:155

8.文件长度相加
ls -l | awk " /^[^d]/ {print $9" "$5} {tot += $5}
END {print "total KB:"tot}"

cat 0
cat_file.txt 28
data.f 356
delete_me_and_die 284
first2 61
grade.txt 235
info.txt 354
myfile 23
test.bak 225
test.sql 225
who.out 1998
wow 229
total KB:4018
查看当前目录下的所有文件：
ls -l
total 24
-rw-r--r-- 1 xxxx group 0 Nov 19 10:12 cat
-rw-r--r-- 1 xxxx group 28 Nov 14 20:32 cat_file.txt
-rw-r--r-- 1 xxxx group 356 Nov 16 19:50 data.f
-rw-r--r-- 1 xxxx group 284 Nov 19 10:36 delete_me_and_die
-rwxr--r-- 1 xxxx group 61 Nov 8 09:15 first2
-rw-r--r-- 1 xxxx group 235 Nov 19 10:44 grade.txt
-rwxr--r-- 1 xxxx group 354 Nov 17 11:05 info.txt
-rwxr----- 1 xxxx group 23 Nov 7 19:12 myfile
-rwxr--r-- 1 xxxx group 225 Nov 15 18:08 test.bak
-rwxr--r-- 1 xxxx group 225 Nov 15 14:12 test.sql
-rw-r--r-- 1 xxxx group 1998 Nov 15 14:15 who.out
-rw-r--r-- 1 xxxx group 229 Nov 19 14:44 wow