What is a C equivalent to this C++ answer for temporarily silencing output to cout/cerr and then restoring it?
How to silence and restore stderr/stdout?
(Need this to silence noise from 3rd party library that I am calling, and to restore after the call.)
This is a terrible hack, but should work:
#include <stdio.h>
#include <unistd.h>
int
suppress_stdout(void)
{
fflush(stdout);
int fd = dup(STDOUT_FILENO);
freopen("/dev/null", "w", stdout);
return fd;
}
void
restore_stdout(int fd)
{
fflush(stdout);
dup2(fd, fileno(stdout));
close(fd);
}
int
main(void)
{
puts("visible");
int fd = suppress_stdout();
puts("this is hidden");
restore_stdout(fd);
puts("visible");
}
#include <stdio.h>
#ifdef _WIN32
#define NULL_DEVICE "NUL:"
#define TTY_DEVICE "COM1:"
#else
#define NULL_DEVICE "/dev/null"
#define TTY_DEVICE "/dev/tty"
#endif
int main() {
printf("hello!\n");
freopen(NULL_DEVICE, "w", stdout);
freopen(NULL_DEVICE, "w", stderr);
printf("you CAN'T see this stdout\n");
fprintf(stderr, "you CAN'T see this stderr\n");
freopen(TTY_DEVICE, "w", stdout);
freopen(TTY_DEVICE, "w", stderr);
printf("you CAN see this stdout\n");
fprintf(stderr, "you CAN see this stderr\n");
return 0;
}