made a bit more robust

diff --git a/modules/src/system/close.c b/modules/src/system/close.c
index 350b72a..3cfcf34 100644 (file)
--- a/modules/src/system/close.c
+++ b/modules/src/system/close.c
@@ -9,7 +9,9 @@
 sys_close(fp)
        register File *fp;
 {
-       fp->o_flags = 0;
-       close(fp->o_fd);
-       fp->o_fd = -1;
+       if (fp) {
+               fp->o_flags = 0;
+               close(fp->o_fd);
+               fp->o_fd = -1;
+       }
 }

diff --git a/modules/src/system/read.c b/modules/src/system/read.c
index 1180234..b88d9d0 100644 (file)
--- a/modules/src/system/read.c
+++ b/modules/src/system/read.c
@@ -12,5 +12,6 @@ sys_read(fp, bufptr, bufsiz, pnbytes)
        char *bufptr;
        int bufsiz, *pnbytes;
 {
+       if (! fp) return 0;
        return (*pnbytes = read(fp->o_fd, bufptr, bufsiz)) >= 0;
 }

diff --git a/modules/src/system/seek.c b/modules/src/system/seek.c
index 2d742fa..132a5fc 100644 (file)
--- a/modules/src/system/seek.c
+++ b/modules/src/system/seek.c
@@ -14,5 +14,6 @@ sys_seek(fp, off, whence, poff)
        long off;
        long *poff;
 {
+       if (! fp) return 0;
        return (*poff = lseek(fp->o_fd, off, whence)) >= 0;
 }

diff --git a/modules/src/system/write.c b/modules/src/system/write.c
index 582ecd3..dd98446 100644 (file)
--- a/modules/src/system/write.c
+++ b/modules/src/system/write.c
@@ -12,5 +12,6 @@ sys_write(fp, bufptr, nbytes)
        char *bufptr;
        int nbytes;
 {
+       if (! fp) return 0;
        return write(fp->o_fd, bufptr, nbytes) == nbytes;
 }