diff options
Diffstat (limited to 'src/lib9pclient/seek.c')
-rw-r--r-- | src/lib9pclient/seek.c | 46 |
1 files changed, 46 insertions, 0 deletions
diff --git a/src/lib9pclient/seek.c b/src/lib9pclient/seek.c new file mode 100644 index 00000000..0785c4b4 --- /dev/null +++ b/src/lib9pclient/seek.c @@ -0,0 +1,46 @@ +#include <u.h> +#include <libc.h> +#include <fcall.h> +#include <9pclient.h> +#include "fsimpl.h" + +vlong +fsseek(CFid *fid, vlong n, int whence) +{ + Dir *d; + + switch(whence){ + case 0: + qlock(&fid->lk); + fid->offset = n; + qunlock(&fid->lk); + break; + case 1: + qlock(&fid->lk); + n += fid->offset; + if(n < 0){ + qunlock(&fid->lk); + werrstr("negative offset"); + return -1; + } + fid->offset = n; + qunlock(&fid->lk); + break; + case 2: + if((d = fsdirfstat(fid)) == nil) + return -1; + n += d->length; + if(n < 0){ + werrstr("negative offset"); + return -1; + } + qlock(&fid->lk); + fid->offset = n; + qunlock(&fid->lk); + break; + default: + werrstr("bad whence in fsseek"); + return -1; + } + return n; +} |