Shell Programming Instances---Implementing subtraction remainder of integers (by using read and script-pass methods)

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1.read read mode: [[Email protected] scripts]# vim read_1.sh   1 #!/bin/bash   2 # Filename: read_1.sh  3 # Describe: Integer  arithmetic  4 # author: lijun  5 # date: 2015-08-24   6 # Version: 1.0.1  7    8 read -p  "please  input two nums:  " a b                     9   10 if [ -z   $a  ] | |  [ -z  $b  ] 11 then 12     echo  "please  Input two nums again. "  13     exit 1 14 fi 15   16 expr $ A + 1 > /dev/null 2>&1 17 retval1=$? 18 expr  $b  + 1 > /dev/null 2>&1 19 retval2=$?  20   21 if [  $RETVAL 1 -ne 0 ] | |  [  $RETVAL 2 -ne 0 ] 22 then 23     echo  "Please input two nums (Must be integer)."  24     exit 2 25 else 26     echo   "a+b=$ (  $a  +  $b  )"  27     echo  "a-b=$ (  $a  -  $b  ) " 28     echo " a*b=$ (  $a  *  $b  ) ) " 29     echo " a/b=$ (  $a  /  $b  ) " 30      echo  "a%b=$ (  $a  %  $b  )"  31     exit  0 32 fi

2. How the script is passed:

[[email protected] scripts]# vim read_2.sh    1 #!/bin/bash                                       2  # Filename: read_2.sh                            3 #  describe: integer arithmetic                   4 # Author: Lijun                                   5 # Date: 2015-08-24                                6 # Version: 1.0.2                                  7                                              8 a=$1                                            9 b=$2                                          10                                             11 if [ $# -ne 2  ]                                 12 then                                           13     echo  "usage: sh  ' basename $0 '  {num1  NUM2} "  &nbSp;           14     exit  1                                    15  fi           16                                                   17 expr  $a  + 1 > /dev/null 2 >&1                    18 RETVAL1=$?                                       19 expr  $b  + 1 > /dev/null 2>&1                    20  retval2=$?                                       21                                                  22 if [   $RETVAL 1 -ne 0 ] | |  [  $RETVAL 2 -NE 0 ]    23 THEN   &Nbsp;                                      24     echo  "Please input two integers (must be  Integer). "  25     exit 2                                     26 else                                          27      echo  "a+b=$ (  $a  +  $b  )"                    28     echo  "a-b=$ (  $a  -  $b  ) "                   29     echo  "a*b=$ (  $a  *  $b  )"                    30      echo  "a/b=$ (  $a  /  $b  )"                    31     echo  "A %b=$ (  $a  %  $b  )) "                   32     exit 0                             &nBsp;       33 fi 

                                         

Another method of 3.  integer judgment: [[email protected] scripts]# vim read_3.sh   1 #!/ bin/bash                                          2 # Filename: read_1.sh                                3 # Describe: Integer arithmetic                      4 #  Author: Lijun                                    5 # date: 2015-08-24                                   6 # Version: 1.0.1                                    7                                              8 read -p  "please  input two nums:  " a b               9                                             10 if [ -z  $a  ] | |  [ -z  $b  ]                          11 then                                          12      echo  "Please input two nums again."            13     exit 1                                     14 fi                                           15                                              16 echo  $a  |egrep -o  "[^0-9]{1,}"  > /dev/null | |  echo  $b  |egrep -o  "[^0-9]{1,}"  > /dev/null && 17  echo  "Please input two nums (Must be integer)." | |  {              18 echo  " a+b=$ (  $a  +  $b   )) "                         19 echo  "a-b=$ (  $a  -  $b   )"                           20 echo  "a*b=$ (  $a  *  $b   )"                           21 echo  "a/b=$ (  $a  /  $b   )"                           22 echo  "a%b=$ (  $a  %  $b   )"                           23 }

Shell Programming Instances---Implementing subtraction remainder of integers (by using read and script-pass methods)