stdout from SWIG-generated PHP extension

I have the following C++ function:

void foo() {
    std::cou开发者_如何转开发t << "bar" << std::endl;
}

I'm porting this to PHP via SWIG. Everything compiles fine and the extension loads properly. I'm able to call foo() from PHP, but I only see the bar output if I run the PHP script from the command line.

$ php script.php
bar

If I load the script in the browser, nothing appears. Why does it not show bar in this case?

You can't print to stdout directly. This will of course only work if you're using the CLI SAPI. Use php_printf or any of these:

//Calls php_output_write
#define PHPWRITE(str, str_len)
//Calls php_output_write_unbuffered
#define PHPWRITE_H(str, str_len)
//Idem:
#define PUTC(c)
#define PUTC_H(c)
#define PUTS(str)
#define PUTS_H(str)
int php_write(void *buf, uint size TSRMLS_DC);
int php_printf(const char *format, ...);
int php_output_write(const char *str, size_t len TSRMLS_DC);
int php_output_write_unbuffered(const char *str, size_t len TSRMLS_DC);
//see the rest of main/output.c