怎么截取前幾個(gè)字符串

city_85

dumpfile=${1}
其中${1}就是 類似YSANALYTICS_20110228.dmp,YSANALYTICS_20110301.dmp YSANALYTICS_20110302.dmp之類.只是日期不能固定.現(xiàn)在我想截取簽名的YSANALYTICS_20110228部分,也就是前20個(gè)字符,然后改為如YSANALYTICS_20110228%U.dmp文件,請問如何截取簽名20個(gè)字符?

ly5066113

echo $1 | sed 's/\(.\{20\}\).*/\1%U.dmp/'

chinaboywg

for file in *.dmp
do
     mv $1 ${1%.*} %U.dmp
done

yinyuemi

echo ${1:0:20}%U.dmp

city_85

不行啊.我表達(dá)不清可能.簡單就是YSANALYTICS_20110302.tgz我要截取YSANALYTICS_20110302這20個(gè)字符,怎么截取

yinyuemi

echo YSANALYTICS_20110302.tgz |cut -c0-20
YSANALYTICS_20110302

city_85

謝謝大哥

L_kernel

1. $ echo 'YSANALYTICS_20110302.tgz' | sed 's/\(.\{20\}\).*/\1/'
   
2. YSANALYTICS_20110302

復(fù)制代碼

Shell_HAT

#str=YSANALYTICS_20110302.tgz #echo ${str:0:20} YSANALYTICS_20110302 #echo $SHELL /bin/bash

#echo YSANALYTICS_20110302.tgz | awk '{print substr($1,1,20)}' YSANALYTICS_20110302

kr_zhang

a.dmp
b.dmp
filename=a.dmp

var=${filename%.dmp}