The typical output recorded into chk file from the command:
wget -O - http://website/file > /dev/null 2>chk &
is something like :
0K .......... .......... .......... .......... .......... 0% 143K 62s
50K .......... .......... .......... .......... .......... 1% 433K 41s
100K .......... .......... .......... .......... .......... 1% 1.20M 30s
150K .......... .......... .......... .......... .......... 2% 259K 31s
200K .......... .......... .......... .......... .......... 2% 83.2M 24s
...
8800K .......... .......... .......... .......... .......... 98% 260K 1s
8850K .......... .......... .......... .......... .......... 98% 329K 0s
8900K .......... .......... .......... .......... .......... 99% 433K 0s
8950K .......... .......... .......... .......... ......... 100% 331K=31s
2017-01-13 13:16:59 (288 KB/s) - written to stdout [9215609/9215609]
The file is updated, line after line, during the whole download process. Well, I need to get only the percentage: 0, 1, 2 ... 99 and nothing more.
The following script do the job, even if not perfectly:
tail -n 5 chk | tail -n 1 | colrm 1 63 | cut -d '%' -f 1
The problem arises when I need to do the same into a bash script, as in the following:
#!/bin/bash
# Test script for getting the percentage number from 'wget' output
i=0
wget -O - http://website/file > /dev/null 2>chk &
sleep 1
while (( $i < 90 ))
do
i=`tail -n 5 chk | tail -n 1 | colrm 1 63 | cut -d '%' -f 1`
echo $i
done
The script starts getting the wanted file, it writes out the chk file, but stops with the error message:
line 9: ((: < 90 : syntax error: operand expected (error token is "< 90 ")
I have tried by using [[ ]], quotes... but doesn't work.
Any idea here to do a better job?
Progress bar with wget, whiptail and GNU sed:
wget --progress=dot 'URL' 2>&1 | sed -un 's/.* \([0-9]\+\)% .*/\1/p' | whiptail --gauge "Download" 7 50 0