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[gapil.git] / sources / FullRead.c

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+/* FullRead.c
+ * 
+ * Copyright (C) 2001 Simone Piccardi
+ * 
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or (at
+ * your option) any later version.
+ * 
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+/****************************************************************
+ *
+ * Routine FullRead
+ * Routine to read an exact number of bytes from a socket
+ *
+ * Author: Simone Piccardi
+ * Jun. 2001
+ *
+ * $Id: FullRead.c,v 1.1 2003/02/02 20:35:33 piccardi Exp $ 
+ *
+ ****************************************************************/
+#include <unistd.h>
+#include <errno.h>
+
+ssize_t FullRead(int fd, void *buf, size_t count) 
+{
+    size_t nleft;
+    ssize_t nread;
+ 
+    nleft = count;
+    while (nleft > 0) {             /* repeat until no left */
+       if ( (nread = read(fd, buf, nleft)) < 0) {
+           if (errno == EINTR) {   /* if interrupted by system call */
+               continue;           /* repeat the loop */
+           } else {
+               return(nread);      /* otherwise exit */
+           }
+       } else if (nread == 0) {    /* EOF */
+           break;                  /* break loop here */ 
+       }
+       nleft -= nread;             /* set left to read */
+       buf +=nread;                /* set pointer */
+    }
+    return (count - nleft);
+}
+