C-and-C++/C3/String-Library-Functions/English-timed

Time	Narration
00:01	Welcome to the spoken-tutorial on String Library Functions in C.
00:07	In this tutorial we will learn
00:09	String Library Functions.
00:11	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,
00:22	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.
00:36	Various operations such as copying, concatenation, searching etc are supported.
00:44	Let us see some of the string library functions.
00:48	Here we have the strncpy function.
00:52	The syntax for this is strncpy(char str1, char str2, and int n );
01:02	It copies first n characters of string str2 into string str1.
01:09	example, char strncpy( char hello, char world, 2);
01:16	The output will be Wollo .
01:21	Here we have Wo from 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);
01:42	It will compare first n characters of string 2 with string 1.
01:48	example int strncmp(char ice, char icecream, and 2);
01:55	The output will be 0.
01:58	Now we will see how to use the string library functions.
02:02	I am going to show you some of the commonly used string functions.
02:07	I have already typed the program on the editor,
02:10	I will open it.
02:12	Here, we have the string length function.
02:15	Note that our file name is strlen.c.
02:20	In this, we will find the length of the string.
02:23	These are the header files as stdio.h and string.h.
02:29	This is our main() function.
02:31	Here we have a character variable 'arr'.
02:35	It stores a value 'Ashwini' .
02:38	Then we have an integer variable len1 .
02:42	Here we will find the length of the string using strlen function.
02:48	The result will be stored in 'len1'.
02:52	Then we print the string and the length of the string.
02:56	And this is our return statement.
02:59	Now let us execute the program.
03:01	Open the terminal window by pressing
03:04	Ctrl, Alt and T keys simultaneously on your keyboard.
03:09	To compile, type: "gcc" space "strlen.c" space “-o” space “str1”. Press Enter.
03:19	Type (dot slash) ./str1. 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.
03:37	Let us see another string function.
03:40	Here we have the string copy function.
03:43	Note that our file name is strcpy.c .
03:48	In this, we will copy the source string into the target string.
03:53	Here we have 'Ice' in the source string, it will be copied to the target string.
03:59	This is our strcpy function
04:02	Here we will 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 gcc space strcpy.c space hyphen o space str2. Press Enter
04:20	Type (dot slash)./str2 . Press Enter .
04:24	The output is displayed as:
04:26	source string = Ice
04:29	target string = Ice
04:32	Now let us see another string function.
04:34	Now we will see the string compare function.
04:37	Note that our file name is strcmp.c.
04:42	In this, we will compare two strings.
04:46	Here we have character variables as str1 and str2 .
04:52	str1 stores the value as 'Ice' and str2 stores the value as 'Cream'.
04:58	Here we have integer variables as i and j.
05:03	In this we will compare the string using the strcmp function.
05:08	Here we compare str1 i.e 'Ice' with 'Hello'.
05:14	The result is stored in i.
05:16	In this we will compare string2 i.e '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 gcc space strcmp.c space hyphen o space str3
05:46	Press Enter.
05:47	Type (dot slash) ./str3
05:50	The output is displayed as 1, 0.
05:54	Come back to our program.
05:56	Here we get 1 and here we get as 0.
06:01	Let us come back to our slides.
06:04	Let us summarize.
06:06	In this tutorial we learned,
06:07	String library functions-
06:09	strlen(),
06:11	strcpy(),
06:13	strcmp(),
06:14	strncpy(),
06:16	and strncmp().
06:19	As an assignemnt,
06:21	write a C Program to concatenate String 'best' and String 'bus'.
06:25	Hint: strcat(char str1, char str2);
06:32	Also explore the other functions in string library.
06:36	Watch the video available at the link shown below.
06:39	It summarizes the Spoken Tutorial project.
06:42	If you do not have good bandwidth, you can download and watch it.
06:46	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@spoken-tutorial.org.
07:03	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.
07:15	More information on this mission is available at the link shown below.
07:20	This is Ashwini Patil from IIT Bombay, signing off.
07:24	Thank you for joining.

Contributors and Content Editors

Krupali, PoojaMoolya, Pratik kamble, Sandhya.np14, Sneha