Add error control to iofile

write can write less bytes than we request, so it is necessary check the
return value, in case of error print a message and don't continnue writing
in the file.
---
 st.c |   39 ++++++++++++++++++++++++++++++---------
 1 file changed, 30 insertions(+), 9 deletions(-)

diff --git a/st.c b/st.c
index f967d2c..e19cefd 100644 (file)
--- a/st.c
+++ b/st.c
@@ -340,6 +340,7 @@ static int utf8encode(long *, char *);
 static int utf8size(char *);
 static int isfullutf8(char *, int);
 
+static ssize_t xwrite(int, char *, size_t);
 static void *xmalloc(size_t);
 static void *xrealloc(void *, size_t);
 static void *xcalloc(size_t nmemb, size_t size);
@@ -379,6 +380,21 @@ static char *opt_embed = NULL;
 static char *opt_class = NULL;
 static char *opt_font = NULL;
 
+
+ssize_t
+xwrite(int fd, char *s, size_t len) {
+       size_t aux = len;
+
+       while(len > 0) {
+               ssize_t r = write(fd, s, len);
+               if(r < 0)
+                       return r;
+               len -= r;
+               s += r;
+       }
+       return aux;
+}
+
 void *
 xmalloc(size_t len) {
        void *p = malloc(len);
@@ -926,13 +942,12 @@ ttynew(void) {
                cmdfd = m;
                signal(SIGCHLD, sigchld);
                if(opt_io) {
-                       if(!strcmp(opt_io, "-")) {
-                               iofd = STDOUT_FILENO;
-                       } else {
-                               if((iofd = open(opt_io, O_WRONLY | O_CREAT, 0666)) < 0) {
-                                       fprintf(stderr, "Error opening %s:%s\n",
-                                               opt_io, strerror(errno));
-                               }
+                       iofd = (!strcmp(opt_io, "-")) ?
+                                 STDOUT_FILENO :
+                                 open(opt_io, O_WRONLY | O_CREAT, 0666);
+                       if(iofd < 0) {
+                               fprintf(stderr, "Error opening %s:%s\n",
+                                       opt_io, strerror(errno));
                        }
                }
        }
@@ -1793,8 +1808,14 @@ tputc(char *c, int len) {
        uchar ascii = *c;
        bool control = ascii < '\x20' || ascii == 0177;
 
-       if(iofd != -1)
-               write(iofd, c, len);
+       if(iofd != -1) {
+               if (xwrite(iofd, c, len) < 0) {
+                       fprintf(stderr, "Error writting in %s:%s\n",
+                               opt_io, strerror(errno));
+                       close(iofd);
+                       iofd = -1;
+               }
+       }
        /*
         * STR sequences must be checked before of anything
         * because it can use some control codes as part of the sequence