grep.sh

#!/bin/bash

success=0
word=22222
filename=/root/1.txt

grep -q "$word" "$filename"
#-q:静默查找，不输出到stdout上

if [ $? -eq $success ];then
  echo "$word found in $filename."
else
  echo "$word not found in $filename."
fi

验证：

[root@logstash ~]# sh grep.sh 
22222 found in /root/1.txt.
[root@logstash ~]#