Is puts reentrant?

Is int puts(const char*); re-entrant? Can I saf开发者_运维百科ely put it into a signal handler?

Here is a table with all functions considered safe for signal handling:

"The following table defines a set of functions that shall be either reentrant or non-interruptible by signals and shall be async-signal-safe."

puts does not seem to be in that list, however per this, it is deemed reentrant, but not async-safe, perhaps why it is not in the above mentioned list.

No it is not, you can however use write(), which is async signal safe, to output messages from a signal handler:

#include <unistd.h>

const char* msg = "The message to print.";
write(STDOUT_FILENO, msg, strlen(msg));