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

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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 filename 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 lenght 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 fuction
03.43 Note that our filename 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 filename is strcmp.c
04.42 In this we will comapre 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 interger variables as i and j
05.03 In this we will compare the string using the strcmp function
05.08 Here we compare str1 ie: 'Ice' with 'Hello'
05.14 The result is stored in i
05.16 In this we will compare string2 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 gcc space strcmp.c space hyphen o space str3
05.46 Press Enter
05.47 Type (dot slash)./str3
05.50 The outpur 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 of.
07.24 Thank you for joining.

Contributors and Content Editors

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