shell小结(14)

venceinfo

#输出换行符echo -e "ok\r\n" #可见expr的优点smInt=`expr $swapmemory / 1000000`fileLen=`expr length $filename`-------------------------------------------------------------------------------------------#如何取得本机的IP：auto_get_IP(){    HOSTNAME=`hostname`    myIp=`grep $HOSTNAME /etc/hosts | grep -v "^#" | head -1 | awk '{print $1}'`}head -1 显示第1行 等价于：head -n 1-------------------------------------------------------------------------------------------cat test.sql sqlplus "system/system@lbs" 与 sqlplus "system/system@lbs" @test.sql的区别：前者执行后自动退出-------------------------------------------------------------------------------------------#awk的用法OS_STD=`cat $CONFIGFILE | grep -w "^OS" | awk -F\= '{print $2}' | grep [^"\ "]`#管道的用法[ -d /opt/informix -a -z "$IFX_VERSION" ] && IFX_VERSION=`cat $ids_install \                | grep "IDSVERSION=" | awk -F\= '{print$2}' | awk -F\; '{print$1}'`-------------------------------------------------------------------------------------------case "a" in"a")   echo "ok"        ;;*)   #此处注意！esac-------------------------------------------------------------------------------------------#if语句的用法 if [ -n "$DB_STD" ] && [ -n "$DB_STD" -a -z "$DB2_NAME" -a -z "$IFX_NAME" -a -z "$ORA_NAME" ]then    [ "$DB2_NAME" != "$DB_STD" ] && TMP_DB2_STD=""fi-------------------------------------------------------------------------------------------#grep用法：#-q：不输出结果，这里我们只利用命令执行的结果返回值:#对于grep，则搜索到了，就返回0，否则返回1rpm -qa|grep -qw ssdif [ $? != 0 ]thenFLog "Ssd not been installed!" 1exit 1fi-------------------------------------------------------------------------------------------#!/bin/bashfunction testFun{index=1while (($index < 10));do      local temp=$index      echo "temp="$temp    let index+=1 #或index=(index+1)done}testFun