diff options
| -rw-r--r-- | blktrace.c | 6 | ||||
| -rw-r--r-- | doc/blktrace.8 | 3 | ||||
| -rw-r--r-- | doc/blktrace.tex | 5 |
3 files changed, 13 insertions, 1 deletions
@@ -2626,6 +2626,12 @@ int main(int argc, char *argv[]) goto out; } + if (ndevs > 1 && output_name && strcmp(output_name, "-") != 0) { + fprintf(stderr, "-o not supported with multiple devices\n"); + ret = 1; + goto out; + } + signal(SIGINT, handle_sigint); signal(SIGHUP, handle_sigint); signal(SIGTERM, handle_sigint); diff --git a/doc/blktrace.8 b/doc/blktrace.8 index ab6a3f3..50b3a62 100644 --- a/doc/blktrace.8 +++ b/doc/blktrace.8 @@ -122,6 +122,9 @@ Specifies number of buffers to use. blktrace defaults to 4 sub buffers. \-\-output=\fIfile\fR .RS Prepend \fIfile\fR to output file name(s) + +This only works when supplying a single device, or when piping the output +via "-o -" with multiple devices. .RE \-r \fIrel-path\fR diff --git a/doc/blktrace.tex b/doc/blktrace.tex index 54fe451..4d8278e 100644 --- a/doc/blktrace.tex +++ b/doc/blktrace.tex @@ -389,7 +389,10 @@ Short & Long & Description \\ \hline\hline -d \emph{dev} & --dev=\emph{dev} & Adds \emph{dev} as a device to trace \\ \hline -k & --kill & Kill on-going trace \\ \hline -n \emph{num-sub} & --num-sub=\emph{num-sub} & Specifies number of buffers to use \\ \hline --o \emph{file} & --output=\emph{file} & Prepend \emph{file} to output file name(s) \\ \hline +-o \emph{file} & --output=\emph{file} & Prepend \emph{file} to output file name(s) \\ + & & \textbf{This only works when using a single device} \\ + & & \textbf{or when piping the output via \texttt{-o -}} \\ + & & \textbf{with multiple devices.} \\ \hline -r \emph{rel-path} & --relay=\emph{rel-path} & Specifies debugfs mount point \\ \hline -V & --version & Outputs version \\ \hline -w \emph{seconds} & --stopwatch=\emph{seconds} & Sets run time to the number of seconds specified \\ \hline |