Updated March 13, 2023
Definition of Nginx if else
Nginx if else is used to do the comparison within if else. Basically, nginx is not supporting the statement of else instead of else we are using a temporary variable in the position if else statement. If the directive has a problem at the time of using with the context of location, sometime it will not work which we are excepting but something it will work which was we are expecting.
What is Nginx if else?
The behavior of if else statement in nginx is non-consistent. The nginx http rewrite module is used to change the request URI by using regular expressions of PCRE, it will redirect the select configurations conditionally. We can process if, written, rewrite and break and set directives. The if else directive module is specified in the server level which was executing sequentially and repeatedly. We can search the location by using if else and the request URI. We can specify if else directive inside into the location of found which is executing sequentially.
Using Nginx if else
Nginx if else is the most commonly used conditional statement used in the server. If else conditional statement is very useful and important. Suppose the specified condition is evaluated as true then the module directive is specified inside the braces and the request is assigned to the configuration of if directive and which was inherited from the directive of if else.
Below example is showing that how we can use if else statement in the server directive to specify the condition. We are putting the code of if else statement into the server directive. We can also write if else statement code into the location directive. As else statement is not available in nginx so in the below example we are using the else variable instead of else statement as follows. In below example, we are declaring the variable name as else to use the statement of if else statement in nginx.
In the below example, we are displaying the different error code of the nginx server by using if else statement. We are displaying the error code as 200 and 403. We are using the http_cookie variable to display the session of the nginx server.
Code –
server {
set $else "something not ok";
if ($http_cookie ~* "session") {
set $else "ok";
}
if ($else = "ok") {
return 200;
}
….. {
return 404;
}
}
Below we are checking the post request by using the curl command. The post request by using the if else statement will retrieve the following result as follows. In the below example, we can see that after executing the post request by using the google website it will show the content type that we are using with this request. Also it will showing the content length which was we are using.
curl -I http://google.io/ -X POST
In the below example, we are redirecting the request by using the query string in the if else statement. For redirecting the statement we are using the curl command and giving query string as input. We are using the google website for redirecting the request. We can see that in below example the http request is showing that the 404 error which was showing the page not found. Same error condition which was we are used in the above example of if else statement. We can also use if else statement with the location directive to define the location of the file.
Nginx if else statement
if else statement is very useful while checking the condition of the specified directive. We can check the condition by using the if else statement. At the time of using if else statement it is evaluated as true of false. If suppose while using if else statement is if evaluated as true then the else block is not executing. If suppose if condition block is false then it will checking the false block to execute the statement.
In below syntax we are using the server directive. We can also use another directive to define the syntax of the if else statement.
Syntax –
if ($name ~* "value") {
set $variable_name as else "value of variable";
}
if ($variable_name = " variable_value") {
return statement;
}In the below example, we are using the location directive to define the nginx if else statement. While using the location directive into if else statement it will showing the post request into the location directive as follows.
Code –
location /tmp1 {
tmp_files /file @fallback;
set $true 1;
if ($true) {
set $else "false";
}
}
In the above example, we have used the location folder as a /tmp1, we have also used tmp_files as a file folder. First we have set value of true variable as 1 if suppose value is true then it will execute if block otherwise it will execute else block.
Nginx if else Examples
The below example shows nginx if else statements are as follows. In below example we are using the server directive to define the example of nginx if-else as follows.
Code:
server {
set $else "page is not working properly";
if ($http_cookie ~* "user session") {
set $else " page working as expected ";
}
if ($else = "page working as expected") {
return 200;
}
In the below example, we are using the location directive to define the example of nginx if else as follows. We are using a two-location directive to define the example of if else statement in nginx.
Code:
location /tmp1 {
tmp_files /file @fallback;
set $true 1;
if ($true) {
set $else "false";
}
}
location /tmp2 {
tmp_files /file @fallback;
set $true 1;
if ($true) {
set $else "error";
}
}
Conclusion
We can process if, written, rewrite and break and set directives. If else directive module is specified on to the nginx server level which was executing sequentially and repeatedly. We can specify if else directive inside into the location of found which is executing sequentially.
Recommended Articles
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