fputc, fputs, putc, putchar, puts - output of characters and
int fputc(int c, FILE *stream));
int fputs(const char *s, FILE *stream));
int putc(int c, FILE *stream));
int putchar(int c);
int puts(const char *s);
int ungetc(int c, FILE *stream));
fputc() writes the character c, cast to an unsigned char, to
fputs() writes the string s to stream, without its trailing
putc() is equivalent to fputc() except that it may be imple-
mented as a macro which evaluates stream more than once.
putchar(c); is equivalent to putc(c,stdout)).
puts() writes the string s and a trailing newline to stdout.
Calls to the functions described here can be mixed with each
other and with calls to other output functions from the
stdio library for the same output stream.
fputc(), putc() and putchar() return the character written
as an unsigned char cast to an int or EOF on error.
puts() and fputs() return a non - negative number on suc-
cess, or EOF on error.
ANSI - C, POSIX.1
It is not advisable to mix calls to output functions from
the stdio library with low - level calls to write() for the
file descriptor associated with the same output stream; the
results will be undefined and very probably not what you
write(2), fopen(3), fwrite(3), gets(3), fseek(3), ferror(3)