bash binary operator expected

Condition testTo determine whether a demand is satisfied, it needs to be implemented by a testing mechanism.different test conditions are expressed according to the execution status result of the command1, according to the execution status of the ID

In Linux shell programming, it is often used to determine whether a string is equal, the operator that can be used to determine whether a string is equal (equal), ' (not equal To), ' (less than), ' (Less -eq -ne -lt -le than or equal -gt to), '

As operations personnel, often use Linux know, under Linux, a lot of commands, keywords, looks like a long, but the actual application can be found sometimes there is a difference, of course, the person who is not careful perhaps you will never

When it comes to programming, we are all not unfamiliar, but in Linux, we mainly do script writing. Of course, in order to understand the scripting of Linux, we have to first say the logical relationship of multi-command execution.1. Command

Conditional expression ("CONDITIONAL EXPRESSIONS") Conditional expressions are used in [composite commands and built-in command test and [to test file properties for string and arithmetic comparisons.] An expression is constructed using the

Test Condition Expression Description File symbols: [Root@lamp test]# Help testtest:test [expr]Evaluate conditional expression.Exits with a status of 0 (True) or 1 (false) depending onThe evaluation of EXPR.  Expressions May is unary or binary.

Original address: http://blog.chinaunix.net/uid-24607609-id-2118151.htmlThe syntax for the most streamlined if command is:if TEST-COMMANDS; then CONSEQUENT-COMMANDS; fiafter the Test-command executes and its return status is 0, the

FreeBSD is an important branch of UNIX systems, and its commands are mostly common to Linux, and few of them are unique. 1:man online query man ls2:ls Viewing directories and Archives Ls-la3:ln creating a linked file

MongoDB: Gathering Pipeline, It appears in MongoDB2.2. A data aggregation framework based on data processing pipeline conceptual modeling. The document enters a multi-stage pipeline that can convert the document into clustering results. The

Original address: http://www.cnblogs.com/engeng/articles/5959335.htmlRecently, the interview is often asked this question, want to interview the interviewer wants to examine the network knowledge, see whether this knowledge has formed the