Shell Script - syntax error near unexpected token `else'

Question

With the following shell script, why I am getting errors

syntax error near unexpected token `else'

Shell Script

echo "please enter username"
read user_name
echo "please enter password"
read -s pass
echo ${ORACLE_SID}
SID=${ORACLE_SID}
if ["${ORACLE_SID}" != 'Test'] then
sqlplus -s -l $USER_NAME/$PASS@$SID <<EOF
copy from scott/tiger@orcl insert EMP using select * from EMP
exit
EOF
else
echo "Cannot copy"
fi

Solution 1

You have to terminate the condition of if like this:

if [ "${ORACLE_SID}" != 'Test' ]; then
                                ^ semicolon

or like this:

if [ "${ORACLE_SID}" != 'Test' ]
then
                                ^ newline

Note: you also have to put spaces after [ and before ].

The reason for the ; or linebreak is that the condition part of the if statement is just a command. Any command of any length to be precise. The shell executes that command, examines the exit status of the command, and then decides whether to execute the then part or the else part.

Because the command can be of any length there needs to be a marker to mark the end of the condition part. That is the ; or the newline, followed by then.

The reason for the spaces after [ is because [ is a command. Usually a builtin of the shell. The shell executes the command [ with the rest as parameters, including the ] as mandatory last parameter. If you do not put a space after [ the shell will try to execute [whatever as command and fail.

The reason for space before the ] is similar. Because otherwise it will not be recognized as a parameter of its own.

Solution 2

You may easily check your shell scripts using ShellCheck online (also available as a standalone tool).

In this case, it will point out that the if-statement needs spaces, after [ and before ], and that you need a ; (or a newline) before the then on the same line.

When you've fixed that, it will go on to tell you that USER_NAME is used without being initialized to anything. This is because you also have a user_name variable (case matters). The same is true for PASS and pass.

It also tells you to use read -r to stop read from mangling \ (could be important for passwords, for example), and that you should double quote the variables when calling sqlplus to prevent the shell from accidentally doing file name globbing and word splitting (again this is important if the password, for example, contains file globbing characters like *, or spaces).

Indenting the code will make it more readable too:

#!/bin/bash

read -r -p 'please enter username: ' user_name
IFS= read -rs -p 'please enter password: ' pass

printf 'ORACLE_SID = %s\n' "$ORACLE_SID"
sid=$ORACLE_SID

if [ "$sid" = 'Test' ]; then
    echo 'Cannot copy' >&2
    exit 1
fi

sqlplus -s -l "$user_name/$pass@$sid" <<'SQL_END'
copy from scott/tiger@orcl insert EMP using select * from EMP
exit
SQL_END

Here I've also made it possible to use passwords with leading or trailing space characters by temporarily setting IFS to an empty string for the password reading read.

The logic was also changed to bail out if $ORACLE_SID/$sid is Test. This avoids having the main operational part of the script in an if branch.

Solution 3

When writing sh you'd want

if [ "$ORACLE_SID" != "Test" ]
then
  ...
fi

When writing bash

if [[ "$ORACLE_SID" != "Test" ]]
then
  ...
fi

Mind the spaces please. There must be a space between [[ and first operator.

Comments

[Rahul Patil]

paste.ubuntu.com/6013802

[Olivier Dulac]

you may want to edit the line "copy from ...." as it may be currently showing something you don't want to show. (However, I do hope those are already modified infos, as they would be really poor security wise)

[Jacob]

@OlivierDulac If you are referring to username and password in that line then those are known to all Oracle database users. It is common and well known since the beginning of Oracle database.

[Jacob]

@OlivierDulac You are welcome, some info about this dba-oracle.com/t_scott_tiger.htm

[Jacob]

That was spot on, however now I am getting test.sh: line 6: [: missing ]'`

[Marek Zakrzewski]

@lesmana. A good way to provide a wrong answer first, then keep editing before someone else provides the correct answer. Please try to provide the correct answer the first time.

[Lesmana]

I do not consider my first answer as wrong. In fact, it was "spot on". It just did not solve all the problems in the question.

[Gilles 'SO- stop being evil']

if is syntax, it isn't an ordinary command. It's a reserved word. Unlike many other programming languages, the shell doesn't recognize reserved words everywhere, only when they're the first word of a command (with a few subtleties).

[Stéphane Chazelas]

Note that if ([ x = x ]) then (echo yes) fi also works.

[Kusalananda]

@StéphaneChazelas Ah, yes. And that may be interesting form the point of view of a program generating shell code, but it's not how one usually writes if statements with [ ... ]... :-)