| Message ID | 1556112460-20434-1-git-send-email-yejun.guo@intel.com |
|---|---|
| State | Superseded |
| Headers | show |
> log_file(){ > log BEGIN $1 > - pr -n -t $1 >> $logfile > + i=1 Shell variables are global. This means that any part of the code which ends up calling `log_file` directly or through some other function (and not isolated in a subshell) will get its `i` variable clobbered by `log_file`. This can be very tricky to debug and identify. Please use a variable name which is unlikely to be used by other functions, like `log_file_i`. Same goes for `line` below. This is critical especially in functions which end up get called by a lot of other function - like `log_file`. > + while read line;do This needs to be `while IFS= read -r line; do`. Without the IFS= part trailing white spaces will be trimmed, and without the -r part backslash ('\') will be interpreted an an escape char. > + printf '%5s %s\n' "${i}" "${line}" > + i=$(($i+1)) > + done < $1 >> $logfile While the previous version of the function used `$1` unquoted, it's generally a very bad practice, as it cannot handle white spaces in file names and is subjected to globbing and open for attacks. In general always quote _all_ strings unless you know for a fact that it's not required. In this case it _is_ required. > log END $1 > }
diff --git a/configure b/configure index 8941063..9d2d7be 100755 --- a/configure +++ b/configure @@ -503,7 +503,11 @@ log(){ log_file(){ log BEGIN $1 - pr -n -t $1 >> $logfile + i=1 + while read line;do + printf '%5s %s\n' "${i}" "${line}" + i=$(($i+1)) + done < $1 >> $logfile log END $1 }
It is part of change from https://trac.ffmpeg.org/ticket/5680 provided by Kylie McClain <somasis@exherbo.org> at Wed, 29 Jun 2016 16:37:20 -0400. That change contains two parts, in function log_file and in function print_in_columns. The second part is not good, so I have send out a new patch for print_in_columns. As for the change in the first part, it is good. Just to make the whole thing completed, i send out this patch to copy exactally the change in function log_file. contributor: Kylie McClain <somasis@exherbo.org> Signed-off-by: Guo, Yejun <yejun.guo@intel.com> --- configure | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-)