Eliminate repeating invocation of shell tools by using the pipe more efficently

This reduces the number of forks and saves more than 50% of the conversion time

1 files changed, 5 insertions, 10 deletions

diff --git a/src/makecolumns.sh b/src/makecolumns.sh
index 6f6f9d9..b41b454 100755
--- a/src/makecolumns.sh
+++ b/src/makecolumns.sh
@@ -202,17 +202,12 @@ handle_new_format() {
     numfiles=`find . -name file_\* | wc -l`
     printf "done.\n"
 
-    printf "Splitting decompressed chunks into their columns (11 total) ... "
-    for column in `jot - 0 10 1`; do
+    printf "Splitting decompressed chunks into their columns (11 total) ... 0, "
+    for file in `jot - 0 $(( numfiles - 1 )) 11`; do printf "file_%05X " ${file}; done | xargs cat | xxd -ps -c1 > column_0
+
+    for column in `jot 10`; do
       printf "%d, " $column
-      for file in `jot - ${column} $(( numfiles - 1 )) 11`; do
-        acton=`printf file_%05X ${file}`
-        if [ ${column} = 0 ]; then
-          xxd -ps -c1 ${acton} >> column_0;
-        else
-          tr '\n\0' '\t\n' < ${acton} >> column_${column};
-        fi
-     done;
+      for file in `jot - ${column} $numfiles 11`; do printf "file_%05X " ${file}; done | xargs cat | tr '\n\0' '\t\n' > column_${column}
     done
     printf "done.\n"