Integer expression expected error in shell script

Question

I m a newbie to shell scripts so I have a question  What Im doing wrong in this code      bin bash echo   Write in your age    read age if     age  -le  7   -o     age  -ge   65    then echo   You can walk in for free   elif     age  -gt  7   -a     age  -lt  65   then echo   You have to pay for ticket   fi   When I m trying to open this script it asks me for my age and then it says     bilet sh  line 6     7   integer expression expected   bilet sh  line 9     missing       I don t have any idea what I m doing wrong  If someone could tell me how to fix it I would be thankful  sorry for my poor English I hope you guys can understand me

User · Accepted Answer

You can use this syntax      bin bash  echo   Write in your age    read age  if      age  -le 7      age  -ge 65      then     echo   You can walk in for free   elif      age  -gt 7  amp  amp    age  -lt 65      then     echo   You have to pay for ticket   fi

User · Answer

bilet sh  line 6     7   integer expression expected   Be careful with        bilet sh  line 9     missing       This is because you need to have space between brackets like   if     age  -le 7   -o     age  -ge 65     look  added space  and no

User · Answer

If you are using -o  or -a   it needs to be inside the brackets of the test command   if     age  -le  7  -o   age  -ge   65      However  their use is deprecated  and you should use separate test commands joined by     or  amp  amp   instead   if     age  -le  7           age  -ge   65      Make sure the closing brackets are preceded with whitespace  as they are technically arguments to    not simply syntax   In bash and some other shells  you can use the superior    expression as shown in kamituel s answer  The above will work in any POSIX-compliant shell

User · Answer

If you are just comparing numbers  I think there s no need to change syntax  just correct those lines  lines 6 and 9 brackets      Line 6 before  if     age  -le  7   -o     age  -ge   65      After  if     age  -le  7  -o   age  -ge  65        Line 9 before  elif     age  -gt  7   -a     age  -lt  65     After  elif     age  -gt  7  -a   age  -lt  65

User · Answer

This error can also happen if the variable you are comparing has hidden characters that are not numbers digits   For example  if you are retrieving an integer from a third-party script  you must ensure that the returned string does not contain hidden characters  like   n  or   r    For example      bin bash    Simulate an invalid number string returned   from a script  which is  1234 n  a  1234    if     a  -gt 1233     then     echo  number is bigger  else     echo  number is smaller  fi   This will result in a script error   integer expression expected because  a contains a non-digit newline character   n   You have to remove this character using the instructions here  How to remove carriage return from a string in Bash  So use something like this      bin bash    Simulate an invalid number string returned   from a script  which is  1234 n  a  1234      Remove all new line  carriage return  tab characters   from the string  to allow integer comparison a    a      t r n       if     a  -gt 1233     then     echo  number is bigger  else     echo  number is smaller  fi   You can also use set -xv to debug your bash script and reveal these hidden characters  See https   www linuxquestions org questions linux-newbie-8 bash-script-error-integer-expression-expected-934465

User · Answer

Try this   If    a -lt 4         a -gt 64     then  n      Something something  n elif    a -gt 4         a -lt 64     then  n      Something something  n else  n     Yes it works for me     n

[bash] Integer expression expected error in shell script

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