特殊字符匹配处理

hinux

例如换行、退格这样的特殊字符，怎样赋值给变量，并且判断变量如果存储的是换行则执行某一处理动作？
似乎对于输入输出shell可以做的不是很多。

haimming

1. 
   
2. [rockfall@tmp]$a="a\nb\tc"
   
3. [rockfall@tmp]$echo -e $a
   
4. a
   
5. b        c
   
6. [rockfall@tmp]$echo  $a|grep "\n"&&echo Y||echo N
   
7. a\nb\tc
   
8. Y
   
9. [rockfall@tmp]$echo  $a|grep "k"&&echo Y||echo N
   
10. N
    

复制代码

是这个意思吗？

[ 本帖最后由 haimming 于 2009-2-13 12:02 编辑 ]

hinux

差不多是这样，但：
root@test # a="a\nb\tc";echo $a                           
a\nb\tc
root@test # a="a\nb\tc";echo $a|grep "\\n"&&echo Y||echo N
N
root@test # a="a\nb\tc";echo -e $a|grep "\\n"&&echo Y||echo N
N
root@test #

例如：
stty raw -echo
char=`dd if=/dev/tty bs=1 count=1 2>/dev/null`
stty sane

现在打算判断输入给char的字符是换行或是退格或是制表符怎么判断？

hinux

没人晓得吗？？？

haimming

其它的好弄，制表，换行和退格好像难搞点

waker

NL=$(echo -e '\012')
[ "$char" = "$NL" ] && echo the char is newline

hinux

感谢各位的回复，我已找到我想要的答案了，在这里贡献一段代码，参考了别人的一些内容，做了一些改进。代码的作用：把终端输入的字符赋值给变量，当终端输入为“Backspace”时回删一个输入字符，当输入为“Enter”时对一个变量的赋值完毕。对于password的输入，回显为“*”。并且每个变量的长度不超过35个字符。这里关键的一个地方是“Backspace”和“Enter”的特殊字符“^H”和“^M”的输入，这些字符一定要手敲，不能复制粘贴。Ctrl+v再按下Backupspace键就可以键入Backupspace的特殊字符；Ctrl+v再按下Enter键就可以键入Enter键的特殊字符。

#!/bin/bash
get_char(){
stty raw
stty -echo
eval $1="`dd if=/dev/tty bs=1 count=1 2>/dev/null`"
stty echo
stty cooked
}

get_hide_password(){
COUNT="0"
while :;do
  get_char char
  if [ "$char" = "^M" ];then
    break;
  elif [ "$char" = "^H" ];then
    if [ "$COUNT" -gt "0" ];then
      echo -e "\b\b  \b\c";COUNT="`expr $COUNT - 1`"
      continue;
    else
      continue;
    fi
  fi
  if [ "$COUNT" -lt "36" ];then
    PWDSTR="$PWDSTR$char";echo -e "*\c";COUNT="`expr $COUNT + 1`"
  fi
done
if [ "$COUNT" = "0" ]||[ -z "$COUNT" ];then
  PWDSTR="";
else
  PWDSTR="`echo "$PWDSTR" | cut -c 0-"$COUNT"`"
fi
eval $1="$PWDSTR"
unset char PWDSTR COUNT
}

get_public_input(){
COUNT="0"
while :;do
  get_char char
  if [ "$char" = "^M" ];then
    break;
  elif [ "$char" = "^H" ];then
    if [ "$COUNT" -gt "0" ];then
      echo -e "\b \b\c";COUNT="`expr $COUNT - 1`"
      continue;
    else
      continue;
    fi
  fi
  if [ "$COUNT" -lt "36" ];then
    INPUTSTR="$INPUTSTR$char";echo -e "$char\c";COUNT="`expr $COUNT + 1`"
  fi
done
if [ "$COUNT" = "0" ]||[ -z "$COUNT" ];then
  INPUTSTR="";
else
  INPUTSTR="`echo "$INPUTSTR" | cut -c 0-"$COUNT"`"
fi
eval $1="$INPUTSTR"
unset char INPUTSTR COUNT
}

clear   
tput cup 2 0;echo "####################################################################"
tput cup 3 15;echo "User: "
tput cup 4 15;echo "Password: "
tput cup 5 15;echo "Database: "
tput cup 6 15;echo "Connect as: "
tput cup 7 0;echo "####################################################################"
tput cup 3 21;get_public_input USER;
tput cup 4 25;get_hide_password PSWD;
tput cup 5 25;get_public_input DABE;
tput cup 6 27;get_public_input CTAS;
echo -e "\n"
echo "$USER"
echo "$PSWD"
echo "$DABE"
echo "$CTAS"

hinux

脚本还有些不完善的地方，当给变量赋予“`”、“"”等符号时是会出错的，仍需要改进。

hinux

Sorry，程序有些问题，修改一下：
#!/bin/bash
get_char(){
stty raw
stty -echo
eval $1="`dd if=/dev/tty bs=1 count=1 2>/dev/null`"
stty echo
stty cooked
}

get_hide_password(){
COUNT="0"
while :;do
  get_char char
  if [ "$char" = "^M" ];then
    break;
  elif [ "$char" = "^?" ]||[ "$char" = "^H" ];then
    if [ "$COUNT" -gt "0" ];then
      PWDSTR="`echo "$PWDSTR" | cut -c 0-"$COUNT"`"
      echo -e "\b  \b\c";COUNT="`expr $COUNT - 1`"
      continue;
    else
      PWDSTR=""
      continue;
    fi
  fi
  if [ "$COUNT" -lt "36" ];then
    PWDSTR="$PWDSTR$char";echo -e "*\c";COUNT="`expr $COUNT + 1`"
  fi
done
eval $1="$PWDSTR"
unset char PWDSTR COUNT
}

get_public_input(){
COUNT="0"
while :;do
  get_char char
  if [ "$char" = "^M" ];then
    break;
  elif [ "$char" = "^?" ]||[ "$char" = "^H" ];then
    if [ "$COUNT" -gt "0" ];then
      INPUTSTR="`echo "$INPUTSTR" | cut -c 0-"$COUNT"`"
      echo -e "\b \b\c";COUNT="`expr $COUNT - 1`"
      continue;
    else
      INPUTSTR=""
      continue;
    fi
  fi
  if [ "$COUNT" -lt "36" ];then
    INPUTSTR="$INPUTSTR$char";echo -e "$char\c";COUNT="`expr $COUNT + 1`"
  fi
done
eval $1="$INPUTSTR"
unset char INPUTSTR COUNT
}

clear   
tput cup 2 0;echo "####################################################################"
tput cup 3 15;echo "User: "
tput cup 4 15;echo "Password: "
tput cup 5 15;echo "Database: "
tput cup 6 15;echo "Connect as: "
tput cup 7 0;echo "####################################################################"
tput cup 3 21;get_public_input USER;
tput cup 4 25;get_hide_password PSWD;
tput cup 5 25;get_public_input DABE;
tput cup 6 27;get_public_input CTAS;
echo -e "\n"
echo "$USER"
echo "$PSWD"
echo "$DABE"
echo "$CTAS"