C-language string processing functions

1. Copying strings

Function Prototypes:

Char *strcpy (char *dest,char *src);

Function Description: Copies the string that the SRC points to (ending with '/') to the address space pointed to by dest, and returns a pointer to Dest.

Extension: Copies the first n bytes pointed to by SRC to the address space pointed to by dest

Function Prototypes:

Char *strncpy (char *dest,char *src,int maxlen);

2. String concatenation

Function Prototypes:

Char *strcat (char *dest,char *src);

Function Description: Add the string that the SRC points to at the end of the dest (overwrite the ' + ' at the end of the dest) and add '% ' to return a pointer to Dest.

3. Find the position of the first occurrence of character C in the string str

Function Prototypes:

Char *STRCHR (char *str,char c);

Function Description: Returns a pointer to the position of the first occurrence of C, failing to return null.

Extension: Find the position of the last occurrence of character C in the string str

Function Prototypes:

Char *STRRCHR (char *str,char c);

4. String comparisons

Function Prototypes:

int strcmp (char *str1,char *str2);

Function Description: Two strings are compared from left to right by character (by ASCII values until different characters are encountered or "/"). If STR1>STR2 returns a positive number, STR1=STR2 returns 0,STR1<STR2 returns a negative number.

Extensions: String comparisons regardless of case

Function Prototypes:

int stricmp (char *str1,char *str2);

5. String inversion

Function Prototypes:

Char *strrev (char *str);

Function Description: Reverses the order of all characters in the string str (not including ' s '). Returns a pointer to a string after the reversed order.

6. Find the first occurrence of another string in the specified string

Function Prototypes:

Char *strstr (char *str1,char *str2);

Function Description: If STR2 is a str1 string, it returns the address of the first occurrence of str2 in str1, otherwise returns null;

C-language string processing functions