#include <strings.h>
ignores the size to compare whether two characters are equal. If S1>S2 returns a number greater than 0.
If S1 = S2 Returns a 0. If S1<s2 returns a number less than 0.
/************************************************************************************************************** ********************/
#strcmp (const char *S1, const char *S2)
#int strcasecmp (const char *S1, const char *S2);
#int strncasecmp (const char *S1, const char *S2, size_t N);
#
#DESCRIPTION
#The strcasecmp () function compares the strings S1 and S2, ignoring the case of the characters.
#It returns an integer less than, equal to, or greater than zero if S1 is found,
#respectively, to is less than, to match, or is greater than S2.
#The strncasecmp () function is similar, except it's only compares the first n characters of S1.
DEMO
/************************************************************************* > File name:strcmp.c > Author: Silent Lamb > Mail: [email protected] > Created time:2014 November 08 Saturday 21:38 59 sec. ************************* /#include <stdio.h> #include <stdlib.h> #include < String.h>int Main (int argc, char **argv) {int i = 0;if (argc = = 3) {i = strcasecmp (argv[1],argv[2]), if (i>0) {printf ("Ar GV[1] =%s i =%d\n ", argv[1],i);} else if (i<0) {printf ("argv[2] =%s\n,i =%d\n", argv[2],i);} else{printf ("i =%d\n", i);}} Else{perror ("args error \ n"); exit (1);} Exit (0);}
*************************************************************************************************************** *******************/
Gets the first position that the character C appears in S, or the last position.
/************************************************************************************************************** ********************/
#include <strings.h>
#char *index (const char *s, int c);
#
#DESCRIPTION
#The index () function returns a pointer to the first occurrence of the character C in the string S.
#
#这个函数返回一个指针, it points to the position where the character C first appears in S.
#
#
#char *rindex (const char *s, int c);
#The Rindex () function returns a pointer to the last occurrence of the character C in the string S.
#
#这个函数返回一个指针, which points to the last occurrence of the character C in S.
#
#
#这两个参数的返回值:
#
#The index () and Rindex () functions return a pointer to the matched character or NULL if the character was not found.
#这个index () and Rindex () functions. Returns a pointer to a matching character, or null because the character was not found.
DEMO
/************************************************************************* > File name:index.c > Author: Silent Lamb > Mail: [email protected] > Created time:2014 November 08 Saturday 21:55 18 sec. ************************* /#include <stdio.h> #include <stdlib.h> #include < String.h>int Main (int argc, char **argv) {int i = 0;char * C;IF (argc = = 3) {c = index (argv[1], (*argv[2])); fprintf (stdout , "%s\n", c); Fflush (NULL);} Else{perror ("args error \ n"); exit (1);} Exit (0);}
/************************************************************************************************************** ********************/
String copy function.
/************************************************************************************************************** ********************/
#include <string.h>
#
#char *stpcpy (char *dest, const char *SRC);
#Feature Test Macro Requirements for glibc (see Feature_test_macros (7)):
#stpcpy ():
# Since GLIBC 2.10:
#_XOPEN_SOURCE >= 700 | | _posix_c_source >= 200809L
#Before GLIBC 2.1
#_GNU_SOURCE
#DESCRIPTION
#The stpcpy () function copies the string pointed to by SRC (including the terminating null byte (' ")") to the array PO Inted to by Dest.
#The strings may not overlap, and the destination string dest must is large enough to receive the copy. 。
#
#
/************************************************************************* > File name:stpcpy.c > Author: Silent Lamb > Mail: [email protected] > Created time:2014 November 08 Saturday 22:20 54 Sec. ************************* /#include <stdio.h> #include <string.h>int main (void) { Char a[200] = "ABCDE"; char *b = "dddd\n"; stpcpy (A, B);p rintf ("a =%s\n", a);}
Character array join function. SRC connected to dest back
/************************************************************************************************************** ********************/
#
#
# #include <string.h>
#char *strcat (char *dest, const char *SRC);
#char *strncat (char *dest, const char *SRC, size_t N);
#DESCRIPTION
#The strcat () function appends the SRC string to the dest string, overwriting the terminating null byte ('% ') at the E nd of Dest,
#and then adds a terminating null byte. The strings may not overlap, and the dest string must has enough space for the result. ‘‘)
#
# adds a character array to the target character array. He will add a null to the target character array as the end of the target. This character may be coincident, and adding the target array must have enough space.
#
# This function is similar to the STRNCAT function, but the STRNCAT has an input buffer bounds check
Same as the index function. Gets the position of the first occurrence of a character in a character array. The latter is the last place to appear.
/************************************************************************************************************** ********************/
# #include <string.h>
#
# char *STRCHR (const char *s, int c);
#
# char *STRRCHR (const char *s, int c);
#
# #define _GNU_SOURCE/* See Feature_test_macros (7) */
# #include <string.h>
# char *strchrnul (const char *s, int c);
#
#DESCRIPTION
#The STRCHR () function returns a pointer to the first occurrence of the character C in the string S.
#The STRRCHR () function returns a pointer to the last occurrence of the character C in the string S.
#
#//The function returns a pointer to the first position of the character C in S.
#
#//The function returns a pointer to the last position of the character C in S.
#
#
/************************************************************************* > File name:index.c > Author: Silent Lamb > Mail: [email protected] > Created time:2014 November 08 Saturday 21:55 18 sec. ************************* /#include <stdio.h> #include <stdlib.h> #include < String.h>int Main (int argc, char **argv) {int i = 0;char * C;IF (argc = = 3) {//c = index (argv[1], (*argv[2])); c = STRCHR (a Rgv[1], (*argv[2])); fprintf (stdout, "%s\n", c); Fflush (NULL);} Else{perror ("args error \ n"); exit (1);} Exit (0);}
Determine how many characters in s are not present in the accept.
/************************************************************************************************************** ********************/
#//returns how many characters in a row are not present in the accept. Return to this location.
# #include <string.h>
# size_t strspn (const char *s, const char *accept);
# size_t strcspn (const char *s, const char *reject);
#
# DESCRIPTION
# the STRSPN () function calculates the length of the initial segment of s which consists entirely of characters in accept .
#
# the STRCSPN () function calculates the length of the initial segment of s which consists entirely of characters not in Reject.
#
# RETURN VALUE
# the STRSPN () function returns the number of characters in the initial segment of s which consist only of characters From Accept.
#
# the STRCSPN () function returns the number of characters in the initial segment of S which is not in the string rejec T.
#
#
#
Divides the character string into multiple characters using a separator symbol.
After the function is called, the return value points to the pointer in front of the delimiter.
STRINGNGP points to the character following the delimiter.
/************************************************************************************************************** ********************/
#char *strsep (char **stringp, const char *delim);
#include <string.h>
#char *strsep (char **stringp, const char *delim);
#
# Feature Test Macro Requirements for glibc (see Feature_test_macros (7)):
# STRSEP (): _bsd_source
#
#DESCRIPTION
#If *STRINGP is null, the STRSEP () function returns NULL and does nothing else. Otherwise, this function finds the first token in the string *stringp,
#
# where tokens is delimited by symbols in the string Delim.
#
#This token is terminated by overwriting the delimiter with a null byte (' + ') and *STRINGP is updated-point past the T Oken.
#
#In case No delimiter were found, the token is taken to being the entire string *stringp, and *STRINGP is made NULL.
#
#RETURN VALUE
#
#The strsep () function returns a pointer to the token, which is, it returns the original value of *STRINGP.
#
#
/************************************************************************* > File name:index.c > Author: Silent Lamb > Mail: [email protected] > Created time:2014 November 08 Saturday 21:55 18 sec. ************************* /#include <stdio.h> #include <stdlib.h> #include < String.h>int Main (int argc, char **argv) {int i = 0;char * C;IF (argc = = 3) {//c = index (argv[1], (*argv[2]));//c = STRCHR (Argv[1], (*argv[2]));. /a.out name=zshh0604 =//name = zshh0604c = Strsep (&argv[1],argv[2]); fprintf (stdout, "%s\n", c); fprintf (stdout, "%s\ N ", argv[1]); Fflush (NULL);} Else{perror ("args error \ n"); exit (1);} Exit (0);}
Finds a substring in a function.
/************************************************************************************************************** ********************/
#include <string.h>
#
# char *strstr (const char *haystack, const char *needle);
#
# #define _GNU_SOURCE/* See Feature_test_macros (7) */
#
# #include <string.h>
#
# char *strcasestr (const char *haystack, const char *needle);
#
# DESCRIPTION
# the STRSTR () function finds the first occurrence of the substring needle in the string haystack. The terminating null bytes (' \ ") is not compared.")
/************************************************************************* > File name:strstr.c > Author: Silent Lamb > Mail: [email protected] > Created time:2014 November 08 Saturday 23:18 25 sec. ************************* /#include <stdio.h> #include <stdlib.h> #include < String.h>int Main (void) {char * a = "aaaabbbbb"; char * b = "AB"; char *c = Null;c = Strstr (A, B);p rintf ("c =%s", c); exit (0 );}
Copy S to the space of a malloc and then return it.
Char *strdup (const char *s);
Randomly swaps characters in a character array.
Char *strfry (char *string);
Finds the position of the character array s in how a character first appears in Accpet.
Char *strpbrk (const char *s, const char *accept);
Use Delim to find the character array.
Char *strtok (char *s, const char *delim);
Quite with copy functions.
size_t strxfrm (char *dest, const char *SRC, size_t N);
Summary of Linux C string library functions
