Programming in C

470 Appendix B The Standard C Library

A few other useful definitions from this header file are as follows:

Define Meaning

intptr_t Integer guaranteed to hold any pointer value

uintptr_t Unsigned integer guaranteed to hold any pointer value

intmax_t Largest signed integer type

uintmax_t Largest unsigned integer type

String Functions

The following functions perform operations on character arrays. In the description of

these routines,s,s1,and s2represent pointers to null-terminated character arrays,cis an

int,and nrepresents an integer of type size_t(defined in stddef.h). For the strnxxx

routines,s1and s2can point to character arrays that aren’t null-terminated.

To use any of these functions, you should include the header file <string.h>in your

program:

#include <string.h>

char *strcat (s1, s2)

Concatenates the character strings2to the end ofs1, placing a null character at the

end of the final string.The function returns s1.

char *strchr (s, c)

Searches the string sfor the first occurrence of the character c. If it is found, a point-

er to the character is returned; otherwise, a null pointer is returned.

int strcmp (s1, s2)

Compares strings s1and s2and returns a value less than zero if s1is less than s2,

equal to zero if s1is equal to s2, and greater than zero if s1is greater than s2.

char *strcoll (s1, s2)

Is like strcmp, except s1and s2are pointers to strings represented in the current

locale.

char *strcpy (s1, s2)

Copies the string s2to s1,returning s1.

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