1 files changed, 106 insertions, 0 deletions
diff --git a/io.c b/io.c
new file mode 100644
index 0000000..615f346
--- /dev/null
+++ b/io.c
@@ -0,0 +1,106 @@
+#include <string.h>
+#include <errno.h>
+#include <unistd.h>
+#include <stdarg.h>
+#include <sys/stat.h>
+#include <stdio.h>
+#include <fcntl.h>
+#include <netdb.h>
+#include <netinet/in.h>
+
+#include "io.h"
+
+int read_all(int fd, unsigned char *buf, size_t len) {
+	ssize_t nbytes;
+	while (len > 0) {
+		nbytes = read(fd, buf, len);
+		if (nbytes == 0) { errno = EPIPE; return -1; }
+		if (nbytes < 0 && errno == EINTR) continue;
+		if (nbytes < 0) return -1;
+		buf += nbytes;
+		len -= nbytes;
+	}
+	return 0;
+}
+
+int read_some(int fd, unsigned char *buf, size_t *lenp) {
+	ssize_t nbytes;
+	do nbytes = read(fd, buf, *lenp);
+	while (nbytes < 0 && errno == EINTR);
+	if (nbytes == 0) { errno = EPIPE; return -1; }
+	if (nbytes < 0) return -1;
+	*lenp = nbytes;
+	return 0;
+}
+
+int write_all(int fd, const unsigned char *buf, size_t count) {
+	ssize_t nbytes;
+	while (count > 0) {
+		nbytes = write(fd, buf, count);
+		if (nbytes < 0 && errno == EINTR) continue;
+		if (nbytes < 0) return -1;
+		buf += nbytes;
+		count -= nbytes;
+	}
+	return 0;
+}
+
+ssize_t read_file(char *buf, size_t len, const char *fmt, ...) {
+	va_list ap;
+	int rc;
+	struct stat st;
+	int fd;
+
+	va_start(ap, fmt);
+	rc = vsnprintf(buf, len, fmt, ap);
+	va_end(ap);
+	if (rc < 0) return -1;
+	if ((size_t)rc >= len) { errno = ENAMETOOLONG; return -1; }
+
+	rc = stat(buf, &st);
+	if (rc < 0) return -1;
+	if ((size_t)st.st_size > len-1) { errno = EMSGSIZE; return -1; }
+
+	fd = open(buf, O_RDONLY);
+	if (fd < 0) return -1;
+
+	rc = read_all(fd, buf, st.st_size);
+	if (rc < 0) return -1;
+
+	buf[(size_t)st.st_size] = '\0';
+
+	close(fd);
+	return st.st_size;
+}
+
+int tcp_connect(const char *host, const char *port, const char **errp) {
+	struct addrinfo hints;
+	struct addrinfo *result, *rp;
+	int s;
+	int fd;
+	int err;
+
+	memset(&hints, 0, sizeof(hints));
+	hints.ai_family = AF_UNSPEC;
+	hints.ai_protocol = IPPROTO_TCP;
+
+	if (host && host[0] == '\0') host = NULL;
+	s = getaddrinfo(host, port, &hints, &result);
+	if (s < 0) {
+		*errp = gai_strerror(s);
+		return -1;
+	}
+
+	for (rp = result; rp; rp = rp->ai_next) {
+		fd = socket(rp->ai_family, rp->ai_socktype, rp->ai_protocol);
+		if (fd < 0) continue;
+		if (connect(fd, rp->ai_addr, rp->ai_addrlen) == 0) break;
+		err = errno;
+		close(fd);
+		errno = err;
+	}
+	if (rp == NULL) fd = -1;
+
+	freeaddrinfo(result);
+	return fd;
+}