C String function

C Edit strcpyPrototype: extern char *strcpy (char *dest,char *src), usage: #include <string.h> function: Copy the string from the end of the NUL referred to by SRC to the array referred to by Dest. Returns a pointer to the character (NUL) at the end of the dest. Example://Strcpy.c#include <syslib.h> #include <string.h>main () {char *s= "Golden Global View"; Char D[20];clrscr (); strcpy (d,s);p rintf ("%s", d); GetChar (); return 0;}strcatPrototype: extern char *strcat (char *dest,char *src), usage: #include <string.h> function: Add the string src refers to at the end of the Dest (overwrite the dest at the end) and add ' '. Returns a pointer to the dest. Example://Strcat.c#include <syslib.h> #include <string.h>main () {char d[20]= "Golden Global"; char *s= "View"; CLRSCR (); strcat (d,s);p rintf ("%s", d); GetChar (); return 0;}strlenPrototype: extern int strlen (char *s); Usage: #include <string.h> function: Calculates the length of the string s description: Returns the length of S, excluding the Terminator null. Example://Strlen.c#include <syslib.h> #include <string.h>main () {char *s= "Golden Global View"; CLRSCR ();p rintf ( "%s has%d chars", S,strlen (s)); GetChar (); return 0;}StrncatPrototype: extern char *strncat (char *dest,char *src,int N), usage: #include <string.h> function: Adds the first n characters of the string src refers to at the end of the Dest ( Overwrite the ' dest ' at the end of the range and add '/'. Returns a pointer to the dest. Example://Strncat.c#include <syslib.h> #include <string.h>main () {char d[20]= "Golden Global"; char *s= "View Winide Library "; Clrscr (); Strncat (d,s,5);p rintf ("%s ", d); GetChar (); return 0;}strncpyPrototype: extern char *strncpy (char *dest, char *src, int n); Usage: #include <string.h> Function: Copies the first n bytes of a string that is referred to by the NULL as SRC to the array referred to by Dest. Description: If the first n bytes of Src do not contain a null character, the result will not end with a null character. If the src length is less than n bytes, the dest is padded with null until n bytes are copied. The memory areas referred to by SRC and dest cannot overlap and dest must have enough space to accommodate the SRC string. Returns a pointer to the dest. Example://Strncpy.c#include <syslib.h> #include <string.h>main () {char *s= "Golden Global View"; char *d= "Hello, GGV programmers "; Char *p=strdup (s); Clrscr (); TextMode (0x00); Enable 6 lines modestrncpy (D,s,strlen (s));p rintf ("%s\n", D), strncpy (P,s,strlen (d));p rintf ("%s", p); free (p); GetChar (); return 0;}strcspnFunction: Finds the segment usage of the first given character set content in a string: int strcspn (char *str1, char *str2); program example: #include <stdio.h> #include <string.h># Include <alloc.h>int main (void) {char *string1 = "1234567890"; char *string2 = "747DC8"; int length;length = STRCSPN (s Tring1, string2);p rintf ("Character where strings intersect is at position%dn", length); return 0;}StrDupFunction: Copy the string to the new location usage: char *strdup (char *str); program example: #include <stdio.h> #include <string.h> #include <alloc.h& Gt;int Main (void) {char *dup_str, *string = "ABCDE";d up_str = StrDup (String);p rintf ("%sn", dup_str); free (DUP_STR); return 0;}stricmpFunction: Comparison of two string usages in case insensitive manner: int stricmp (char *str1, char *str2); program example: #include <string.h> #include <stdio.h>int main (void) {Char *buf1 = "BBB", *buf2 = "BBB"; int ptr;ptr = STRICMP (Buf2, BUF1), if (ptr > 0) printf ("Buffer 2 is greater than Buffe R 1n "), if (PTR < 0) printf (" Buffer 2 is less than buffer 1n "), if (ptr = = 0) printf (" Buffer 2 equals buffer 1n "); return 0; }strerrorFunction: Returns a pointer to the error message string usage: char *strerror (int errnum); program example: #include <stdio.h> #include <errno.h>int main (void) { Char *buffer;buffer = strerror (errno);p rintf ("Error:%sn", buffer); return 0;}strcmpFunction: Compare one string with another: Intstrcmpi (char *str1, char *str2); program example: #include <string.h> #include <stdio.h>int main ( void) {char *buf1 = "BBB", *buf2 = "BBB"; int ptr;ptr =strcmpi (buf2, BUF1), if (ptr > 0) printf ("Buffer 2 is greater than B Uffer 1n "), if (PTR < 0) printf (" Buffer 2 is less than buffer 1n "), if (ptr = = 0) printf (" Buffer 2 equals buffer 1n "); retur n 0;}strncmpFunction: Compares a part of a string to a part of another string (first n characters) usage: int strncmp (char *str1, char *str2,int maxlen); program example: #include <string.h> #include & Lt;stdio.h>int Main (void) {char *buf1 = "BBBCCC", *buf2 = "BBBCCC"; int ptr;ptr = STRNCMP (buf2,buf1,3); if (ptr > 0) pri NTF ("Buffer 2 is greater than buffer 1n"), if (PTR < 0) printf ("Buffer 2 is less than buffer 1n"), if (ptr = = 0) printf ("Bu Ffer 2 equals buffer 1n "); return 0;}strnicmpFunction: Compare the first n characters of two strings in a case-insensitive manner: intstrnicmp (char *str1, char *str2, unsigned maxlen); program example: #include <string.h> #include &L T;stdio.h>int Main (void) {char *buf1 = "BBBCCC", *buf2 = "BBBCCC"; int ptr;ptr =strnicmp (buf2, BUF1, 3); if (ptr > 0) pr intf ("Buffer 2 is greater than buffer 1n"), if (PTR < 0) printf ("Buffer 2 is less than buffer 1n"), if (ptr = = 0) printf ("B Uffer 2 equals buffer 1n "); return 0;}StrnsetFunction: Sets all characters in a string to the specified character usage: char *strnset (char *str, char ch, unsigned n); program example: #include <stdio.h> #include <string.h >int Main (void) {Char letter = ' x ';p rintf ("string beforestrnset:%sn", String), Strnset (string, letter,);p rintf (" String Afterstrnset:%sn ", string); return 0;}strpbrkFunction: Find character usage in a given character set in a string: Char *strpbrk (char *str1, char *str2); program example: #include <stdio.h> #include <string.h>int ma In (void) {char *string1 = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"; char *string2 = "onm"; char *ptr;ptr = STRPBRK (string1, string2); if (PTR) printf ("Strpbrk found first character:%cn", *ptr); elseprintf ("strpbrk didn ' t find character in Setn"); return 0;}STRRCHRFunction: Finds the last occurrence of a specified character in a string usage: char *strrchr (char *str, char c); program example: #include <string.h> #include <stdio.h>int main ( void) {char String[15];char *ptr, C = ' R '; strcpy (String, "This is a string");p tr = STRRCHR (string, c); if (PTR) printf ("The C Haracter%c is at position:%dn ", C, ptr-string); elseprintf (" The character were not Foundn "); return 0;}StrrevFunction: String reversal usage: char *strrev (char *str); program example: #include <string.h> #include <stdio.h>int main (void) {char *forward = " String ";p rintf (" Before Strrev ():%sn ", forward), Strrev (forward);p rintf (" After Strrev ():%sn ", forward); return 0;}StrsetFunction: Sets all characters in a string to the specified character usage: char *strset (char *str, char c); program example: #include <stdio.h> #include <string.h>int main ( void) {char string[10] = "123456789"; char symbol = ' C ';p rintf ("Beforestrset ():%sn", string); Strset (string, symbol); printf ("Afterstrset ():%sn", string); return 0;}strspnFunction: Returns the first character in a string that does not appear in the specified string subscript usage: int strspn (char *str1, char *str2); program example: #include <stdio.h> #include <string.h& gt; #include <alloc.h>int main (void) {char *string1 = "1234567890"; char *string2 = "123DC8"; int length;length = STRSP N (string1, string2);p rintf ("Character where strings differ is at position%dn", length); return 0;}strstrFunction: Finds the first occurrence of a specified string in a string usage: char *strstr (char *str1, char *str2); program example: #include <stdio.h> #include <string.h>int m Ain (void) {char *str1 = "Borland International", *STR2 = "Nation", *ptr;ptr = Strstr (str1, str2);p rintf ("The substring is: %sn ", PTR); return 0;}strtodFunction: Converts a string to a double strtod (char *str, char **endptr); program example: #include <stdio.h> #include <stdlib.h> int main (void) {char input[80], *endptr;double value;printf ("Enter A floating point number:"), gets (input), value = Strtod ( Input, &endptr);p rintf ("The string is%s the number is%LFN", input, value); return 0;}strtokFunction: Finds the word usage delimited by the delimiter specified in the second string: Char *strtok (char *str1, char *str2); program example: #include <string.h> #include <stdio.h >int Main (void) {char input[16] = "Abc,d"; char *p;/* strtok places a NULL Terminatorin front of the token, if found */p = Strtok (Input, ","); if (p) printf ("%sn", p);/* A second call to Strtok using a Nullas the first parameter returns A point Erto the character following the token */p = Strtok (NULL, ","); if (p) printf ("%sn", p); return 0;}StrtolFunction: Convert string to Long integer usage: long strtol (char *str, char **endptr, int base); program example: #include <stdlib.h> #include <stdio.h>int Main (void) {char *string = "87654321", *endptr;long lnumber;/* strtol converts string to Long integer */lnumber = strtol (s Tring, &endptr,;p rintf ("string =%s long =%ldn", string, Lnumber); return 0;}STRUPRFunction: Converts lowercase letters in strings to uppercase usage: char *strupr (char *str); program example: #include <stdio.h> #include <string.h>int main (void) { Char *string = "ABCDEFGHIJKLMNOPQRSTUVWXYZ", *ptr;/* converts string to upper case characters */ptr =STRUPR (string);p rintf ("%sn", PTR); return 0;}Swabfunction: Swap byte usage: void swab (char *from, char *to, int nbytes); program example: #include <stdlib.h> #include <stdio.h> #include & Lt;string.h>char source[15] = "Rfna Koblrna d"; char Target[15];int main (void) {swab (source, target, strlen (source)); printf ("This is target:%SN", target); return 0;} Ps:isalpha () is a character function, not a string function,IsalphaPrototype: extern int isalpha (int c); Usage: #include <ctype.h> function: Determines whether the character C is an English letter description: When C is an English letter A-Z or a-Z, returns a value other than 0, otherwise returns zero. Example://isalpha.c#include <syslib.h> #include <ctype.h> #include <stdio.h>main () {int c;clrscr (); Clear Screenprintf ("press a Key"); for (;;) {C=getchar (); Clrscr ();p rintf ("%c:%s Letter", C,isalpha (c)? " Is ': ' not ');} return 0; Just to avoid warnings by compiler}

C String function