Shell script

What does these two line in shell script mean ? What's the usage for "[ ]" and "&&" ?

  [ $RETVAL = 0 ] && rm -f $lockfile
  return $RETVAL
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AXISHKAsked:
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ozoCommented:
see
man test
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Zephyr ICTCloud ArchitectCommented:
[ ] are used in the shell for performing a conditional test.

&& is used between two command, as AND operator, if 2 commands have && between them, the command on the left (command1) is run first, and the command on the right (command2) is run only if the first command succeeds --> command1 && command2
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ozoCommented:
man bash
       The control operators && and || denote AND lists and OR lists, respectively.  An AND list has the form

              command1 && command2

       command2 is executed if, and only if, command1 returns an exit status of zero.
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AXISHKAuthor Commented:
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Shell Scripting

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