grep awk

xieaotian

1、查找含有IP的文件:#grep "[0-9]\{1,3\}.[0-9]\{1,3\}.[0-9]\{1,3\}.[0-9]\{1-3\}" *(所有文件,*.txt以.txt为后缀的所有文件)
#grep "[0-9]\{3\}.[0-9]\{3\}.[0-9]\{3\}.[0-9]\{3\}" * 只能查找***.***.***.***这种格式的IP,而如192.168.0.2这样的就不匹配了
2、查找当前目录下哪些是目录文件
   #ls -l|grep "^d" (ls -l的结果中以d开头的为目录)
   #ls -l|grep "^[^d]" (查看ls -l的结果中不是以d开头的文件) 同#ls -l|grep ^d -v(-v取反)
grep ^root /etc/passwd (查找/etc/passwd中以root开头的行)
grep -v ^root /etc/passwd (查找/etc/passwd中不以root开头的行)
grep bash$ /etc/passwd (查找/etc/passwd中以bash结尾的行)
grep ^$ /etc/passwd (查找/etc/passwd中的空行)
3、查找一个文件中含有大写字母的行
   #grep "[[:upper:]]" /etc/profile
   或#grep -n "[[:upper:]]" /etc/profile (-n显示匹配行及行号)
    #grep -n "[[:upper:]]" /etc/profile |wc -l （含有大写字母的行数）
grep命令类名：
[[：upper:]] 相当于[A-Z]
[[:lower:]] 相当于[a-z]
[[:digit::]相当于[0-9]
[[:alpha:]] 相当于[a-zA-Z]
[[:space:]] 空格或tab键
[[:alnum:]]相当于[0-9a-zA-Z]


[root@server0 b]# cat txt
/var/log/Xorg.setup.log
/var/log/gdm/:0.log
/var/log/anaconda.log
/var/log/scrollkeeper.log

[root@server0 b]# awk -F '/' '{print NF,NR,ENVIRON["USER"],$4}' txt
4 1 root Xorg.setup.log
5 2 root gdm
4 3 root anaconda.log
4 4 root scrollkeeper.log
[root@server0 b]#
NF浏览记录的域个数,NR已读的记录数,gsub(s,t)用t来替换s
[root@server0 b]# awk -F '/' '{if(gsub("/","#")) print $0}' txt
#var#log#Xorg.setup.log
#var#log#gdm#:0.log
#var#log#anaconda.log
#var#log#scrollkeeper.log
[root@server0 b]#
[root@server0 b]# awk 'BEGIN {split("aa#bb#cc",array,"#");print array[1],"\t",array[2],"\t",array[3]}'
aa       bb      cc  注:awk中的数组是从1开始的,不同于C语言中从0开始
[root@server0 b]#

#!/bin/awk -f
#awk.sh
BEGIN{
FS="#" # -F
score["0-60"]=0
score["60-70"]=0
score["70-80"]=0
score["80-90"]=0
score["90-100"]=0
student["junior"]=0
student["senior"]=0
}
{
   {if($1<60)
    score["0-60"]++
   }
   {if($1<70&&$1>=60)
    score["60-70"]++
   }
   {if($1<80&&$1>=70)
    score["70-80"]++
   }
   {if($1<90&&$1>=80)
     score["80-90"]++
   }
   {if($1<=100&&$1>=90)
     score["90-100"]++
   }
}
{
   for(juniorsenior in student)
    {if($2==juniorsenior)
     student[juniorsenior]++
    }
}
END{
     { for(number in score)print "the score",number,"has",score[number],"students"}
     {for(juniorsenior in student)print "the class has",student[juniorsenior],"students"}
}  
注:符号"{"要直接跟在BEGIN,END后面
[root@server0 b]# cat grade
35#senior
45#junior
65#junior
69#senior
69#junior
45#senior
72#junior
78#senior
80#junior
85#junior
90#senior
91#junior
96#junior
[root@server0 b]#

[root@server0 b]# ./awk.sh grade
the score 0-60 has 3 students
the score 70-80 has 2 students
the score 90-100 has 3 students
the score 60-70 has 3 students
the score 80-90 has 2 students
the class has 5 students
the class has 8 students
[root@server0 b]#


#!/bin/bash
#datelog
current_date=`date "+%Y%m%d"`
echo $current_date
todaylog="log/${current_date}.log" #当前目录下必须有log目录,否则会提示log目录或文件不存在
echo $todaylog
#if [ ! -f $todaylog ]
#then
#   touch $todaylog
#fi   #这四行可以注释掉      
log_time_format=`date "+%Y-%m-%d %T"`
echo "$log_time_format command begin">>$todaylog
echo ">>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>"
sleep 4 #停留4秒
echo ">>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>"
log_time_format=`date "+%Y-%m-%d %T"`  # %T小时:分钟:秒
echo "$log_time_format command end">>$todaylog

[root@server0 b]#


在脚本中捕捉信号:
[root@server0 ~]# cat trap1.sh
#!/bin/bash
#trap1.sh
trap "exitprocess" 2 注:信号2的含义:来自键盘的中断信号,通常是<ctrl+c>
loop=0
function exitprocess()
{
echo "you just hit <ctrl-c>,at number $loop"
echo "I will now exit"
exit 1
}
while :
do
  loop=$[$loop+1]
  echo $loop
  sleep 1
done
[root@server0 ~]#