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Strstr() in the C language is a crafted-in perform. The features of strstr can be understandable via the manual current in the Ubuntu terminal if you are functioning on Ubuntu. Then the terminal will present you the tutorial of strstr and how it works.

Example 1

Take into account the first example of strstr we have made use of the code in a file. And we will get the output by this file in the terminal. As it is acknowledged that the enter of strstr are two strings, in which just one string’s event is determined in the other string. To begin with the library header “string.h” will be used that handles several capabilities of string. If this library is not released, it is not attainable to execute a system of string capabilities. The string function utilized in this supply code is

In this, p is a pointer. S1 and S2 are two strings. We need to have to locate the prevalence of s2 in the string s1. To print out the final results, we have used an if-else statement to implement the condition that checks the to start with occurrence of the string. If the unique substring is existing in the principal string, it will be exhibited with a affirmation message. If it is not current, then a message will be displayed.

In the higher than screenshot, you can see an input string from which you want to recognize the compact string. That modest string is also talked about if the statement will take p as an argument in the parameter, as the value of the strstr operate is saved in it.

If you are doing work on Linux running system and want to get the output. Then this can be done by applying a pair of commands on the Ubuntu terminal. The to start with command is for the compilation

For compilation, we will need a compiler, the GCC made use of for Linux to compile a C method on it. “-o” is utilised to retail outlet the consequence in an output file from the supply file.  Now the future action is the execution.

This is completed by working with a dot process. In which we use a dot and a slash with the identify of the file.

The output displays that the substring was current and also reveals its area in the file.

Example 2

This is a further basic illustration of the strstr() purpose with no the use of if-assertion. In this C software, we will match a certain term in the string and then fetch it as the word is matched in accordance to its prevalence. Then in the output, the phrase and the figures current together with the substring are also exhibited.

Output = strstr(a, searchstring)

As the event is attained by using the pointer variable in the code. Since this pointer is employed to get the spot of the substring and to see the substring, we use only the variable title with out asterisk in the output command. If we want to display the place, then we will use the pointer( variable with an asterisk), i.e., *output.

You can see this in the output. The word ”function” was to be searched as a substring. The people, together with the substring, are also shown.

Example 3

In this code, we will initial obtain the occurrence of the sub-string, and then this sub-string will be changed with a different string. Once more two strings will be reserved as enter. Just one is the big string, and the other is a term that will be replaced immediately after its event will be established. The strstr purpose matches the compact sub-string with the primary a person. And when the match is founded for the pretty initially time, it returns the value. But in this illustration, this value is more replaced. Let us see how it will get the job done.

The place p will keep the worth of prevalence in it, S1 and s2 are the input strings.

Now we have the stage of prevalence of that input string. Now we will substitute this string with the other term. This is accomplished in the physique of the if assertion. This shows that if the problem is genuine, the phrase is started, then replaced by yet another phrase. This replacement is performed by way of a different string purpose.

We want to replace the phrase with “strstr”. In which p is the location of the first incidence of that substring which the functionality has replaced. Strcpy() replaces these two words and phrases in the string. The output will be attained by the exact compile-execution approach.

From the output, you can see that the string is now changed with the other term we have described in the strcpy functionality.

Case in point 4

This illustration demonstrates the similar idea. In this article we have taken free area as a character in addition to the word as a substring. It is a uncomplicated illustration in which we don’t even have applied if-assertion. Only the match and screen concept is used. Two strings are taken as enter. In addition, the word is shown with the concept. The strstr will work in the similar way.

Right here c is the variable the place the occurrence position will be stored.

Now, we will get hold of the output.

From the output, you can recognize that place is also counted with the substring we have released.

Illustration 5

This instance is fairly unique from the preceding types. Below we have employed a separate perform to accomplish the motion of strstr() instead of the key software. In comparison, the values will be handed as arguments in the parameters of the perform contact. In this case in point, we have outlined the substring, and the software, right after execution, will display the posture of the initially prevalence alternatively of the benefit in the output. The function will receive the values in the variables, and then we will use the strstr() on these variables. If-else assertion is utilized to check the availability and to make the problem true and if it is untrue, then move to the else portion.

Char* pos = strstr(str, substr)

Whilst str is a string, substr is a substring. Char*pos is the place of the initial prevalence of a substring in the string. The indicator ‘%s’ existing in the assertion that is displayed implies changing a substring and the total string. As substring is existing before the string in the parameter.

Now transferring towards the principal application. For starters a string is launched that will be passed as a result of a purpose simply call

Discover_str( str , “best”)

Below we have also added the substring with the string. Every time a new substring is additional. The second time we have extra a cost-free room character. The 3rd time, a substring that is not a part of the string is extra. And in the final, an alphabet is utilized.

Use the instructions and then see the result appended under.

Right here is the outcome of the C plan operate phone calls. The 1st two and 4th statements satisfy the situation, so the answer is exhibited. The third 1 is not applicable, so the else aspect will manage this.


In this report, the usage of strstr is discussed, along with illustrations. These examples show wide range in working with that idea in lots of methods. The string capabilities are uncomplicated to use in the existence of their header in the library.

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