Convenience macro for libssh2_channel_setenv_ex(3) calls
#include <libssh2.h>
int libssh2_channel_setenv(LIBSSH2_CHANNEL *channel, const char *varname, const char *value);
This is a macro defined in a public libssh2 header file that is using the underlying function libssh2_channel_setenv_ex(3).