The document provides an overview of various string library functions in C, including examples and output for functions such as strlen(), strcmp(), strcpy(), strcat(), and others. Each function is explained with its syntax and illustrative code snippets. This guide serves as a reference for understanding how to manipulate strings using standard library functions.

1. Strings
String library functions
Nishma jagadish 1

2. String library functions
Strlen()
Strcmp()
Strcpy()
Strcat()
Strncpy()
Strncat()
Strncmp()
Strchr()
Strrchr()
Strstr()
Nishma jagadish 2

3. Strlen()
Size_t strlen (char const *string);
Eg:
main()
{
Int l;
Char str[20];
Str[]=“nishma”;
L=strlen (str);
Printf(“length = %d”,l);
}
o/p : length=6
Nishma jagadish 3

4. Strcmp()
int strcmp (const char *str1, const char *str2);
Eg:
main()
{
Int l;
Char str1[20] , str2[20];
Str1[]=“new”;
Str2[]=“new”;
L=strcmp (str1,str2);
Printf(“%d”,l);
}
o/p : 0
If s1<s2 o/p < 0
If s1==s2 o/p == 0
If s1>s2 o/p > 0
Nishma jagadish 4

5. Strcpy()
Char *strcpy (char *str1 , const char str2);
Eg:
main()
{
Char str1[20], str2[20];
Str1[]=“newyear”;
Str2[]=“York”;
strcpy (str1, str2);
Printf(“str1=%s, str2=%s”,str1,str2);
}
o/p :
Str1=“York”
Str2=“York”
Source
Dest
strcpy (str1, str2);
strcpy (str1, “York”);
strcpy (“new”, str2);
strcpy (“new”, “York”);
Nishma jagadish 5

6. Strcat()
char *strcat (char *str1, const char *str2);
Eg:
main()
{
Char str1[20] , str2[20];
Str1[]=“new”;
Str2[]=“york”;
strcat (str1,str2);
Printf(“str1=%s, str2=%s”,str1,str2);
}
o/p :
Str1=“newyork”
Str2=“York”
Nishma jagadish 6

7. Strncpy()
Char *strncpy (char *str1 , const char str2 , size_t n);
Eg:
main()
{
Int n=6;
Char str1[20], str2[20];
Str1[]=“department”;
Str2[]=household”;
strncpy (str1, str2,n);
Printf(“str1=%s, str2=%s”,str1,str2);
}
o/p :
Str1=“househment”
Str2=“household”
Source
Dest
strncpy (str1, str2,n);
strncpy (str1, “York”,n);
strncpy (“new”, str2,n);
strncpy (“new”, “York”,n);
Nishma jagadish 7

8. Strncat()
char *strncat (char *str1, const char *str2, size_t n);
Eg:
main()
{
Int n =6;
Char str1[20] , str2[20];
Str1[]=“department”;
Str2[]=“household”;
strncat (str1,str2,n);
Printf(“str1=%s, str2=%s”,str1,str2);
}
o/p :
Str1=“departmenthouseh”
Str2=“household”
Nishma jagadish 8

9. Strncmp()
int strncmp (const char *str1, const char *str2, size_t n);
Eg:
main()
{
Int l,n=4;
Char str1[20] , str2[20];
Str1[]=“newyear”;
Str2[]=“newyork”;
L=strncmp (str1,str2,n);
Printf(“%d”,l);
}
o/p :
If n=4, l==0
If n>4, and length of str1<str2, l is negative
If n>4, and length of str1<str2, l is positive
If s1<s2 o/p < 0
If s1==s2 o/p == 0
If s1>s2 o/p > 0
Nishma jagadish 9

10. Strchr()
char *strchr (const char *str , int ch);
Eg:
main()
{
Char str[20],*p;
Str[]=“department”;
P=strchr (str1, ‘e’);
Printf(“p=%s”,p);
}
o/p :
P = epartment
If the char is not present it returns null
First occurance(left most)
Nishma jagadish 10

11. Strrchr()
char *strrchr(const char *str , int ch);
Eg:
main()
{
Char str[20],*p;
Str[]=“department”;
P=strrchr (str, ‘e’);
Printf(“p=%s”,p);
}
o/p :
P = ent
If the char is not present it returns null
Last occurance(right most)
Nishma jagadish 11

12. Strstr()
char *strstr (const *s1 , const char *s2);
Eg:
main()
{
Char str1[20], str2[20];
Str1[]=“destination block”;
Str2[]=“nation”;
P=strstr (str1, str2);
Printf(“str1=%s , str2=%s”,str1,str2);
}
o/p :
Str1=nation block
Str2=nation
If str2 is station this string is not
present in str1 hence returns a
null
Used to locate the first
occurrence of a substring
in another string
Nishma jagadish 12

13. Thank you
Nishma jagadish 13