builtin [ , -bash: [: missing `]'
while going through learn bash the hard way, I found that [ and test are both commands and synonyms, and both are builtin.
As it is a builtin it should not give any error for builtin [ , but I am getting -bash: [: missing `]', Can someone explain me the behavior of builtin here.
Thanks in advance.
anupam:Markdown$ which [
/usr/bin/[
anupam:Markdown$ echo $?
0
anupam:Markdown$ which test
/usr/bin/test
anupam:Markdown$ echo $?
0
anupam:Markdown$ builtin test
anupam:Markdown$ echo $?
1
anupam:Markdown$ builtin [
-bash: [: missing `]'
anupam:Markdown$ echo $?
2
anupam:Markdown$ 1 Answer
The [ version of the command requires ] as the mandatory last parameter (so it must be preceded by a space). It’s just a formal, syntactic thing to force users to close the bracketed “block”, so commands look this way:
if [ $1 -eq 2 ]; theninstead of
if [ $1 -eq 2; thenSee help [:
$ help [
[: [ arg... ] Evaluate conditional expression. This is a synonym for the "test" builtin, but the last argument must be a literal `]', to match the opening `['.Notes
The
testversion does not require nor accept the final].You don’t need the
builtinthere. Builtins take priority over external commands, so just[would execute the builtin. Thebuiltincommand is more useful when you have a function or alias masking[.
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