C-and-C++/C3/String-Library-Functions/English-timed
From Script | Spoken-Tutorial
| Time' | Narration |
| 00:02 | Welcome to the spoken-tutorial on String Library Functions in C |
| 00:07 | In this tutorial, we will learn, |
| 00:10 | String Library Functions |
| 00:12 | We will do this with the help of some examples |
| 00:15 | To record this tutorial, I am using |
| 00:18 | Ubuntu Operating System version 11.10, |
| 00:23 | gcc Compiler Version 4.6.1 |
| 00:27 | Let us start with an introduction to string library functions. |
| 00:31 | These are the group of functions implementing operations on strings. |
| 00:37 | Various operations such as copying, concatenation, searching etc are supported. |
| 00:45 | Let us see some of the string library functions |
| 00:49 | Here we have the strncpy function |
| 00:52 | The syntax for this is strncpy(char str1, char str2, int n ) |
| 01:02 | It copies first n characters of string str2 into string str1. |
| 01:10 | eg. char strncpy(char hello, char world, 2); |
| 01:17 | The output will be ;Wollo |
| 01:21 | Here we have Wo fromt the string 2 and rest of the characters from string 1 |
| 01:29 | Now we will see strncmp function, the syntax for this is strncmp (char str1, char str2 and int n) |
| 01:43 | It will compare first n characters of string 2 with string 1 |
| 01:49 | eg. int strncmp(char ice, char icecream, 2); |
| 01:56 | The output will be 0 |
| 01:58 | Now we will see how to use the string library functions. |
| 02:03 | I am going to show you some of the commonly used string functions. |
| 02:08 | I have already typed the program on the editor, |
| 02:11 | i will open it |
| 02:12 | Here we have the string length function |
| 02:15 | Note that our filename is strlen.c. |
| 02:20 | In this we will find the length of the string |
| 02:24 | These are the header files as stdio.h and string.h |
| 02:29 | This is our main function |
| 02:32 | Here we have a character variable 'arr', |
| 02:36 | It stores a value 'Ashwini' |
| 02:39 | Then we have an integer variable len1
|
| 02:43 | here we will find the lenght of the string using strlen funtion |
| 02:49 | the result will be stored in len1 |
| 02:53 | Then we print the string and the length of the string. |
| 02:57 | And this is our return statement
|
| 02:59 | Now let us execute the program |
| 03:02 | Open the terminal window by pressing |
| 03:04 | Ctrl, Alt and T keys simultaneously on your keyboard |
| 03:10 | To compile |
| 03:11 | Type: "gcc" space "strlen.c" space “-o” space “str1”. |
| 03:19 | Press Enter |
| 03:20 | type: ./str1 |
| 03:23 | Press Enter |
| 03:24 | The output is displayed as |
| 03:26 | string = Ashwini, Length = 7 |
| 03:30 | You can count here. 1,2,3,4,5,6, and 7 |
| 03:38 | Let us see another string function |
| 03:41 | Here we have the string copy fuction |
| 03:43 | Note that our filename is strcpy.c. |
| 03:49 | In this we will copy the source string into the target string |
| 03:54 | Here we have Ice in the source string, it will be copied to the target string . |
| 04:00 | This is our strcpy function |
| 04:03 | Here we print the source string and the target string |
| 04:07 | Let us execute and see |
| 04:09 | Come back to our terminal |
| 04:11 | To compile type |
| 04:12 | gcc space strcpy.c space -o space str2 |
| 04:19 | Press Enter |
| 04:21 | Type ./str2 |
| 04:23 | Press Enter
|
| 04:25 | The output is displayed as |
| 04:27 | source string = Ice |
| 04:30 | target string = Ice |
| 04:32 | Now let us see another string function |
| 04:35 | Now we will see the string compare function |
| 04:38 | Note that our filename is strcmp.c |
| 04:43 | In this we will comapre two strings |
| 04:47 | Here we have character variables as str1 and str2
' |
| 04:53 | str 1 stores the value as 'Ice' and str2 stores the value as 'Cream'. |
| 04:59 | Here we have interger variables as i and j |
| 05:04 | In this we will compare the string using the strcmp function |
| 05: 09 | Here we compare str1 ie: 'Ice' with 'Hello' |
| 05:14 | The result is stored in i |
| 05:17 | In this we will compare string 2 ie: 'Cream' with 'Cream' |
| 05:23 | The result is stored in j |
| 05:25 | Then we print both the results |
| 05:28 | and this is our return statement |
| 05:31 | Let us execute the program. |
| 05:33 | Come back to our terminal. |
| 05:35 | To compile type |
| 05:37 | gcc space strcmp.c space -o space str3 |
| 05:46 | Press Enter |
| 05:48 | Type ./str3 |
| 05:51 | The outpur is displayed as 1,0 |
| 05:55 | Come back to our program |
| 05:57 | Here we get 1 |
| 055:59 | and here we get as 0 |
| 06:02 | Let us move back to our slides |
| 06:04 | Let us summarize, |
| 06:06 | In this tutorial we learned, |
| 06:08 | String library functions |
| 06:09 | strlen() |
| 06:11 | strcpy() |
| 06:13 | strcmp() |
| 06:15 | strncpy() |
| 06:17 | and strncmp()
|
| 06:20 | As an assignemnt, |
| 06:21 | Write a C Program to concatenate String best and String bus. |
| 06:25 | Hint: strcat(char str1, char str2); |
| 06:33 | Also explore the other functions in string library. |
| 06:37 | Watch the video available at the link shown below http://spoken-tutorial.org /What\_is\_a\_Spoken\_Tutorial |
| 06:40 | It summarises the Spoken Tutorial project |
| 06:43 | If you do not have good bandwidth, you can download and watch it. |
| 06:47 | The Spoken Tutorial Project Team |
| 06:49 | Conducts workshops using spoken tutorials |
| 06:52 | Gives certificates to those who pass an online test |
| 06:56 | For more details, please write to contact [at] spoken hyphen tutorial dot org |
| 07:04 | Spoken Tutorial Project is a part of the Talk to a Teacher project |
| 07:08 | It is supported by the National Mission on Education through ICT, MHRD, Government of India |
| 07:16 | More information on this Mission is available at: http://spoken-tutorial.org\NMEICT-Intro |
| 07:21 | This is Ashwini Patil from IIT Bombay. |
| 07:24 | Thank you for joining. |
