Add fdprintf(). Remove reread() and rewrite() which handle -EINTR, which

shouldn't be a problem if we register signal handlers with sigaction(SA_RESTART)
Straighten out count and len (I generally consistently use "count" for the
current progress and "len" for the total, but this time I got them backwards
for some reason and don't want to confuse myself in future.)

3 files changed, 32 insertions, 43 deletions

diff --git a/lib/functions.c b/lib/functions.c
index 98a344a2..ce3edccc 100644
--- a/lib/functions.c
+++ b/lib/functions.c
@@ -174,30 +174,12 @@ FILE *xfopen(char *path, char *mode)
 	return f;
 }
 
-// Read from file handle, retrying if interrupted.
-ssize_t reread(int fd, void *buf, size_t count)
-{
-	for (;;) {
-		ssize_t len = read(fd, buf, count);
-		if (len >= 0  || errno != EINTR) return len;
-	}
-}
-
-// Write to file handle, retrying if interrupted.
-ssize_t rewrite(int fd, void *buf, size_t count)
-{
-	for (;;) {
-		ssize_t len = write(fd, buf, count);
-		if (len >= 0 || errno != EINTR) return len;
-	}
-}
-
 // Keep reading until full or EOF
-ssize_t readall(int fd, void *buf, size_t count)
+ssize_t readall(int fd, void *buf, size_t len)
 {
-	size_t len = 0;
-	while (len<count) {
-		int i = reread(fd, buf, count);
+	size_t count = 0;
+	while (count<len) {
+		int i = read(fd, buf+count, len-count);
 		if (!i) return len;
 		if (i<0) return i;
 		count += i;
@@ -207,13 +189,12 @@ ssize_t readall(int fd, void *buf, size_t count)
 }
 
 // Keep writing until done or EOF
-ssize_t writeall(int fd, void *buf, size_t count)
+ssize_t writeall(int fd, void *buf, size_t len)
 {
-	size_t len = 0;
-	while (len<count) {
-		int i = rewrite(fd, buf, count);
-		if (!i) return len;
-		if (i<0) return i;
+	size_t count = 0;
+	while (count<len) {
+		int i = write(fd, buf+count, len-count);
+		if (i<1) return i;
 		count += i;
 	}
 
@@ -221,22 +202,26 @@ ssize_t writeall(int fd, void *buf, size_t count)
 }
 
 // Die if there's an error other than EOF.
-size_t xread(int fd, void *buf, size_t count)
+size_t xread(int fd, void *buf, size_t len)
 {
-	count = reread(fd, buf, count);
-	if (count < 0) perror_exit("xread");
+	len = read(fd, buf, len);
+	if (len < 0) perror_exit("xread");
 
-	return count;
+	return len;
 }
 
-void xreadall(int fd, void *buf, size_t count)
+void xreadall(int fd, void *buf, size_t len)
 {
-	if (count != readall(fd, buf, count)) perror_exit("xreadall");
+	if (len != readall(fd, buf, len)) perror_exit("xreadall");
 }
 
-void xwrite(int fd, void *buf, size_t count)
+// There's no xwriteall(), just xwrite().  When we read, there may or may not
+// be more data waiting.  When we write, there is data and it had better go
+// somewhere.
+
+void xwrite(int fd, void *buf, size_t len)
 {
-	if (count != writeall(fd, buf, count)) perror_exit("xwrite");
+	if (len != writeall(fd, buf, len)) perror_exit("xwrite");
 }
 
 char *xgetcwd(void)
diff --git a/lib/lib.h b/lib/lib.h
index 24d6f82a..3a7d6507 100644
--- a/lib/lib.h
+++ b/lib/lib.h
@@ -43,13 +43,11 @@ void xaccess(char *path, int flags);
 int xcreate(char *path, int flags, int mode);
 int xopen(char *path, int flags);
 FILE *xfopen(char *path, char *mode);
-ssize_t reread(int fd, void *buf, size_t count);
-ssize_t rewrite(int fd, void *buf, size_t count);
-ssize_t readall(int fd, void *buf, size_t count);
-ssize_t writeall(int fd, void *buf, size_t count);
-size_t xread(int fd, void *buf, size_t count);
-void xreadall(int fd, void *buf, size_t count);
-void xwrite(int fd, void *buf, size_t count);
+ssize_t readall(int fd, void *buf, size_t len);
+ssize_t writeall(int fd, void *buf, size_t len);
+size_t xread(int fd, void *buf, size_t len);
+void xreadall(int fd, void *buf, size_t len);
+void xwrite(int fd, void *buf, size_t len);
 char *xgetcwd(void);
 char *xabspath(char *path);
 struct string_list *find_in_path(char *path, char *filename);
diff --git a/lib/portability.h b/lib/portability.h
index dca0ddea..5aa4a0bf 100644
--- a/lib/portability.h
+++ b/lib/portability.h
@@ -1,3 +1,9 @@
+
+// Humor glibc to get dprintf, then #define it to something more portable.
+#define _GNU_SOURCE
+#include <stdio.h>
+#define fdprintf(...) dprintf(__VA_ARGS__)
+
 #include <endian.h>
 
 #if __BYTE_ORDER == __BIG_ENDIAN