Following the reference to “Bash Conditional Expressions” will lead you to the description of -ne , which is the numeric inequality operator (“ne” stands for “not equal). By contrast, != is the string inequality operator. You can also find bash documentation on the web.
What does ne mean Linux?
ne (for “nice editor“) is a console text editor for POSIX computer operating systems such as Linux or Mac OS X. It uses the terminfo library, but it can also be compiled using a bundled copy of the GNU termcap implementation.
What is $? 0 in bash?
$? is the exit status of the most recently-executed command; by convention, 0 means success and anything else indicates failure.
What is $? UNIX?
The $? variable represents the exit status of the previous command. Exit status is a numerical value returned by every command upon its completion. … For example, some commands differentiate between kinds of errors and will return various exit values depending on the specific type of failure.
What is $0 shell?
$0 expands to the name of the shell or shell script. This is set at shell initialization. If bash is invoked with a file of commands, $0 is set to the name of that file.
Can you use != In bash?
Not Equal “-ne” Operator Syntax
Linux bash not equal operator is expressed with the “-ne” which is the first letter of “not equal”. … =” is used to express not equal operator. The “!= ” is also popularly used in other programming languages for not equal.
What is the meaning of in bash?
1 : to strike violently : hit also : to injure or damage by striking : smash —often used with in. 2 : to attack physically or verbally media bashing celebrity bashing. intransitive verb. : crash. bash away.
What is the meaning of in shell scripting?
A shell script is a text file that contains a sequence of commands for a UNIX-based operating system. It is called a shell script because it combines a sequence of commands, that would otherwise have to be typed into the keyboard one at a time, into a single script.
What is Echo $1?
$1 is the argument passed for shell script. Suppose, you run ./myscript.sh hello 123. then. $1 will be hello.