roughly calculate remaining time, more and better help, small fixes

split-dl.sh

@@ -6,23 +6,39 @@ CHECKSUM="md5sum"   # Define application to create hashsums
 FILE=""
 MODE=""
 
+function help {
+  echo "This program is used to split large files into several small
+files to avoid data loss and the need to re-download them from 
+slow or unstable internet connections."
+  echo
+  echo "Written by Max Mehl <mail@mehl.mx> in 2015."
+  echo
+  echo "Necessary arguments to start this application:"
+  echo "-m    Desired MODE. Possible values are \"server\" or \"client\""
+  echo "      \"server\" splits the file on the server and needs a file for -f."
+  echo "      \"client\" downloads the files and needs a download link for -f."
+  echo "-f    File in the same directory to be splitted or link to be downloaded."
+  echo
+  echo "Optional arguments:"
+  echo "-s    Define the desired size of splitted files. Default is $SPLITSIZE"
+  echo "-i    Define the desired name of the info document. 
+      Default is $INFO"
+  echo "-c    Define the program which should be used to calculate the hashsum. 
+      Default is $CHECKSUM"
+  echo
+  echo "Examples:"
+  echo "Split Hugefile.iso in parts of 50MB and use sha1sum as hashing program."
+  echo "    split-dl -m server -f Hugefile.iso -s 50M -c sha1sum"
+  echo
+  echo "Download the splitted files of Hugefile.iso. 
+The hashing program has to be the same as on the server side."
+  echo "    split-dl -m client -f http://example.com/dl-Hugefile.iso -c sha1sum"
+}
+
 while getopts h:s:i:c:f:m: opt; do
   case $opt in
   h)
-      echo "This program is used to split large files into several small
+      help
-files to avoid data loss and the need to re-download them from 
-slow or unstable internet connections."
-      echo
-      echo "Necessary arguments to start this application:"
-      echo "-m    Desired MODE. Possible values are \"server\" or \"client\""
-      echo "      \"server\" splits the file on the server and needs a file for -f."
-      echo "      \"client\" downloads the files and needs a download link for -f."
-      echo "-f    File in the same directory to be splitted or link to be downloaded."
-      echo
-      echo "Optional arguments:"
-      echo "-s    Define the desired size of splitted files. Default is $SPLITSIZE"
-      echo "-i    Define the desired name of the info document. Default is $INFO"
-      echo "-c    Define the program which should be used to calculate the hashsum. Default is $CHECKSUM"
       exit 0
       ;;
   s)
@@ -46,15 +62,7 @@ done
 # DO NOT EDIT BELOW HERE
 # ----------------------
 
-if [ "$FILE" == "" ] || [ "$MODE" == "" ]; then
+# # # # # # # # # # # # # # # # # # # # # # # # # 
-  echo "Missing arguments! Please define the mode with -m and the file/link with -f. More info with -h."
-  exit 1
-#else
-  #echo "$MODE $SPLITSIZE $INFO $FILE $CHECKSUM"
-fi
-
-
-# # # #
 # FUNCTIONS
 # # # #
 function checkwait {
@@ -76,7 +84,14 @@ function comphash {
 }
 
 function getdu {
-  du -b $1 | awk -F" " '{ print $1 }'
+  DU=$(du -b $1 | awk -F" " '{ print $1 }')
+  if [ -d $1 ] && [ "$BLOCK" != "" ]; then
+    # Reduce the size of an directory by the block size
+    # $BLOCK is defined in the one-time-run section of this script
+    echo $(($DU - $BLOCK))
+  else
+    echo $DU
+  fi
 }
 
 function compdu {
@@ -122,8 +137,27 @@ function checkfolder {
   fi
 }
 
-
+# # # # # # # # # # # # # # # # # # # # # # # # # 
+# ONE-TIME-ACTIONS
 # # # #
+
+# Check if -m and -f are given
+if [ "$FILE" == "" ] || [ "$MODE" == "" ]; then
+  echo "Missing arguments! Please define the mode with -m and the file/link with -f."
+  echo 
+  help
+  exit 1
+#else
+  #echo "$MODE $SPLITSIZE $INFO $FILE $CHECKSUM"
+fi
+
+# Check size in bytes of an empty directory
+TMP=$(mktemp -d)
+BLOCK=$(getdu $TMP)
+rm -r $TMP
+
+
+# # # # # # # # # # # # # # # # # # # # # # # # # 
 # SERVER MODE
 # # # #
 if [ $MODE == "server" ]; then
@@ -167,7 +201,7 @@ checkfolder $FOLDER
 INFONAME=$INFO
 INFO="$FOLDER/$INFONAME"
 
-echo "[INFO] Calculating size and HASH sum..."
+echo "[INFO] Calculating size and hashsum..."
 BIGNAME=$(basename $FILE)
 BIGSIZE=$(getdu $FILE)
 BIGHASH=$(gethash $FILE)
@@ -176,6 +210,11 @@ echo "BIGNAME=$BIGNAME" >> $INFO
 echo "BIGSIZE=$BIGSIZE" >> $INFO
 echo "BIGHASH=$BIGHASH" >> $INFO
 echo >> $INFO
+# Variables info
+echo "CHECKSUM=$CHECKSUM" >> $INFO
+echo "SPLITSIZE=$SPLITSIZE" >> $INFO
+echo "INFO=$INFO" >> $INFO
+echo >> $INFO
 
 echo "[INFO] Splitting big file into smaller parts..."
 split --verbose -a 4 -b $SPLITSIZE $FILE $FOLDER/dl-
@@ -204,7 +243,7 @@ echo "[INFO] Please move the folder \"$FOLDER\" to a web-accessible directory an
 fi # /SERVER MODE
 
 
-# # # #
+# # # # # # # # # # # # # # # # # # # # # # # # # 
 # CLIENT MODE
 # # # #
 if [ $MODE == "client" ]; then
@@ -223,7 +262,7 @@ wget -q $URL/$INFO
 # Rename info.cfg to avoid colissions and source it
 source $INFO
 mv $INFO $BIGNAME-$INFO
-INFO=$BIGNAME-$INFO
+INFO=dl-$BIGNAME-$INFO
 
 FOLDER="dl-$BIGNAME"
 
@@ -239,6 +278,7 @@ echo
 
 checkfolder $FOLDER   # Checks and creates folder
 
+# Downloading every single small file
 until [ "$STATUS" == "F" ]; do
   for ((i = 0; i < ${#SMALLNAME[*]}; i++)); do
     SMALLNAME=${SMALLNAME[$i]}
@@ -256,6 +296,9 @@ until [ "$STATUS" == "F" ]; do
     echo "Already downloaded "$(getdu $FOLDER)" of $BIGSIZE bytes."
     echo 
     
+    # Define starttime
+    TSTART=$(date +"%s")
+    
     # File doesn't exist yet, so start fresh download
     if [ ! -e $SMALLPATH ]; then
       echo "[INFO] File doesn't exist yet. Starting new download."
@@ -282,9 +325,9 @@ until [ "$STATUS" == "F" ]; do
         break
       fi
       
-    # File already exists, has correct size, but has wrong HASH
+    # File already exists, has correct size, but has wrong hashsum
     elif [ -e $SMALLPATH ] && $(compdu $SMALLPATH SMALLSIZE) && ! $(comphash $SMALLPATH $SMALLHASH); then
-      echo "[ERROR] HASH is different but file has same size."
+      echo "[ERROR] Hashsum is different but file has same size."
       echo "[INFO] Deleting file and starting new download." 
       checkwait
       rm $SMALLPATH
@@ -298,7 +341,7 @@ until [ "$STATUS" == "F" ]; do
         break
       fi
     
-    # File already exists, has correct size, and has correct HASH
+    # File already exists, has correct size, and has correct hashsum
     elif [ -e $SMALLPATH ] && $(compdu $SMALLPATH $SMALLSIZE) && $(comphash $SMALLPATH $SMALLHASH); then
       echo "[SUCCESS] File already exists and is valid."
       STATUS="C"
@@ -309,7 +352,19 @@ until [ "$STATUS" == "F" ]; do
       STATUS="E"
     fi
     
-    # Check if download is finished
+    # Define time when the download finished
+    echo
+    TEND=$(date +"%s")
+    TDIFF=$[$TEND-$TSTART]
+    if [ $TDIFF -ge "3" ]; then
+      # Calc bytes per second
+      BPS=$[$SMALLSIZE / $TDIFF]
+      DUDIFF=$[$BIGSIZE - $(getdu $FOLDER)]
+      TREST=$[$DUDIFF / $BPS]
+      echo "[INFO] The last file was downloaded at ~$[$BPS / 1024] KB/s. ETA $(($TREST / 60)):$(($TREST % 60))."
+    fi
+    
+    # Check if all small downloads are finished
     if [ $NO -lt $SMALLNO ]; then
       echo "[INFO] Starting next download."
       STATUS="C"
@@ -341,9 +396,9 @@ if [ $YN == "y" ]; then
   fi
 fi
 
-# Check big file for HASH and size
+# Check big file for hashsum and size
 sleep 2   # In rare cases, this can prevent a wrong du size
-echo "[INFO] Checking correct size and HASH hashsum for rebuilt big file..."
+echo "[INFO] Checking correct size and hashsum for rebuilt big file..."
 
 # Compare sizes
 if $(compdu $BIGNAME $BIGSIZE); then
@@ -352,11 +407,11 @@ else
   echo "[ERROR] The size of the completed file is incorrect."
 fi
 
-# Compare HASH sum
+# Compare hashsum
 if $(comphash $BIGNAME $BIGHASH); then
-  echo "[SUCCESS] The HASH sum of the completed file is corrent."
+  echo "[SUCCESS] The checksum of the completed file is corrent."
 else
-  echo "[ERROR] The HASH sum of the completed file is incorrect."
+  echo "[ERROR] The sum of the completed file is incorrect."
 fi