C

Appendix C

Library Functions

This appendix provides a brief description of the C standard library functions.

<assert.h>

void assert(int exp);

If the value of exp is 0, a diagnostic message is displayed and the program terminates. If not, it does nothing.

<ctype.h>

int isalnum(int ch);

Checks if ch is alphanumeric (a–z, A–Z, 0–9). If it is, it returns a nonzero value, 0 otherwise.

int isalpha(int ch);

Checks if ch is alphabetic (a–z, A–Z). If it is, it returns a nonzero value, 0 otherwise.

int iscntrl(int ch);

Checks if ch is a control character. If it is, it returns a nonzero value, 0 otherwise.

int isdigit(int ch);

Checks if ch is a digit. If it is, it returns a nonzero value, 0 otherwise.

int isgraph(int ch);

Checks if ch is a printable ...