I try to compile the code below:
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <term.h>
//#include "/usr/include/term.h"
void clear_screen(void) {
if (!cur_term) {
int result;
setupterm( NULL, STDOUT_FILENO, &result );
if (result <= 0)
return;
}
putp( tigetstr( "clear" ) );
}
int main(void) {
puts("I am going to clear the screen");
sleep(1);
clear_screen();
puts("Screen Cleared");
sleep(1);
clear_screen();
return 0;
}
This program tests a function that uses the term.h
header file to clear the terminal screen.
I have installed all the libraries needed: libncurses5
and libncurses5-dev
and when I compile the program with or without the -lncurses
, -lcurses
and -lterminfo
parameters to the gcc
compiler I get the above output:
In file included from clear_screen_UNIX.c:5:0:
clear_screen_UNIX.c:9:6: error: expected ‘=’, ‘,’, ‘;’, ‘asm’ or ‘__attribute__’ before ‘->’ token
void clear_screen(void) {
^
clear_screen_UNIX.c: In function ‘main’:
clear_screen_UNIX.c:23:14: error: called object is not a function or function pointer
clear_screen();
^
clear_screen_UNIX.c:26:14: error: called object is not a function or function pointer
clear_screen();
^
Moreover, when I explicitly include the term.h
header using its full path /usr/include/term.h
I get this as the output:
In file included from clear_screen_UNIX.c:7:0:
/usr/include/term.h:125:21: error: expected ‘=’, ‘,’, ‘;’, ‘asm’ or ‘__attribute__’ before ‘->’ token
#define CUR cur_term->type.
^
/usr/include/term.h:202:40: note: in expansion of macro ‘CUR’
#define clear_screen CUR Strings[5]
^
clear_screen_UNIX.c:9:6: note: in expansion of macro ‘clear_screen’
void clear_screen(void) {
^
clear_screen_UNIX.c: In function ‘main’:
clear_screen_UNIX.c:23:14: error: called object is not a function or function pointer
clear_screen();
^
clear_screen_UNIX.c:26:14: error: called object is not a function or function pointer
clear_screen();
^
According to the above, the term.h
header has some mistakes inside, something I do not believe.
So do I need to install some more packages or configure some settings for the code to compile successfully?
PS:
- The code example is from here
- My Ubuntu version is 14.04
Best Answer
Indeed,
clear_screen
is a macro:You will have to use some other name, like the linked page does:
The compiler messages also state this:
That's why the errors seem to be in
term.h
- the macro expansion leads there.