[英]While loop fail to read all line from file
So I got this bash script that perform a backup command from remote server, each server hostname is defined on file called /tmp/quarantine.list
.所以我得到了这个从远程服务器执行备份命令的 bash 脚本,每个服务器主机名都在名为
/tmp/quarantine.list
文件中定义。 The content is like this:内容是这样的:
server1
server2
server1
and server2
is an ssh alias to my remote server, so if I need to access either of them I just run eg ssh server1
. server1
和server2
是我的远程服务器的 ssh 别名,所以如果我需要访问它们中的任何一个,我只需运行例如ssh server1
。
I need to backup each server in /tmp/quarantine.list
, so I loop each line using while
loop.我需要备份
/tmp/quarantine.list
每个服务器,所以我使用while
循环循环每一行。 Here is my code.这是我的代码。
# Reading from /tmp/quarantine.list
while IFS= read -r list; do
if [ "$list" == "server4" ]; then
users="adminjoe"
fi
tempfile="${logdir}/rsync_$list.log"
SECONDS=0
set +x
if rsync -ca --stats --info=progress2 --remove-source-files $list:/home/${users}/backup/20* $backup_location/$list >> $tempfile 2>&1; then
ssh $list "find /home/${users}/backup/20* -type d -empty -delete"
else
echo "Error while running rsync"
exit 1
fi
set -x
elapsed_time=$SECONDS
transferred_size=$(gawk 'BEGIN { FS=":" } {gsub(/^[ \t]+|[ \t]+$/, "", $2)} /Total transferred file size/ { print $2 }' $tempfile | tr -cd "[:digit:]")
echo "Backup of $list done at $(/bin/date +'%Y-%m-%d_%H:%M:%S') --> $(bytesToHumanReadable $transferred_size)" | tee -a "${HOME}/backup.log"
echo "<b>$list --> $(bytesToHumanReadable $transferred_size)</b>" >> $konten
echo "$transferred_size $list" >> $summaryfile_size
echo "$elapsed_time $list" >> $summaryfile_time
done < "/tmp/quarantine.list"
rm "/tmp/quarantine.list"
The problem is my script only pick the first line of /tmp/quarantine.list
, so for example if there was two remote in quarantine.问题是我的脚本只选择
/tmp/quarantine.list
的第一行,例如,如果隔离中有两个远程。
server2
server6
The script only process server2
, while server6
remains untouched.该脚本仅处理
server2
,而server6
保持不变。 What's weird is, when I put --dry-run
option to rsync, it will process all line in /tmp/quarantine.list
without problem !奇怪的是,当我将
--dry-run
选项放入 rsync 时,它将/tmp/quarantine.list
处理/tmp/quarantine.list
中的所有行!
--dry-run
--dry-run
+ echo 'Backup of server2 done at 2021-10-28_16:55:26 --> 3.28 GB'
Backup of server2 done at 2021-10-28_16:55:26 --> 3.28 GB
++ bytesToHumanReadable 3280769140
++ S=("bytes" "kB" "MB" "GB" "TB" "PB" "EB" "YB" "ZB")
++ local i=3280769140 d= s=0 S
++ (( i > 1000 && s < 9-1 ))
++ printf -v d .%02d 14
++ i=3280769
++ s=1
++ (( i > 1000 && s < 9-1 ))
++ printf -v d .%02d 76
++ i=3280
++ s=2
++ (( i > 1000 && s < 9-1 ))
++ printf -v d .%02d 28
++ i=3
++ s=3
++ (( i > 1000 && s < 9-1 ))
++ echo '3.28 GB'
+ echo '<b>server2 --> 3.28 GB</b>'
+ echo '3280769140 server2'
+ echo '1883 server2'
+ IFS=
+ read -r list
+ rm /tmp/quarantine.list
--dry-run
--dry-run
+ echo 'Backup of server2 done at 2021-10-28_16:07:14 --> 3.28 GB'
Backup of server2 done at 2021-10-28_16:07:14 --> 3.28 GB
++ bytesToHumanReadable 3280769140
++ S=("bytes" "kB" "MB" "GB" "TB" "PB" "EB" "YB" "ZB")
++ local i=3280769140 d= s=0 S
++ (( i > 1000 && s < 9-1 ))
++ printf -v d .%02d 14
++ i=3280769
++ s=1
++ (( i > 1000 && s < 9-1 ))
++ printf -v d .%02d 76
++ i=3280
++ s=2
++ (( i > 1000 && s < 9-1 ))
++ printf -v d .%02d 28
++ i=3
++ s=3
++ (( i > 1000 && s < 9-1 ))
++ echo '3.28 GB'
+ echo '<b>server2 --> 3.28 GB</b>'
+ echo '3280769140 server2'
+ echo '32 server2'
+ IFS=
+ read -r list
+ '[' server6 == server4 ']'
As you can see, the latter continues with server6
as opposed of the former.如您所见,后者继续使用
server6
,而不是前者。 I just wondering what I'd do wrong here?我只是想知道我在这里做错了什么?
This can happen if the last line of the file does not end with a newline.如果文件的最后一行不以换行符结尾,就会发生这种情况。 Then
read
will actually read the line, but it will return a non-zero status (ref: https://www.gnu.org/software/bash/manual/bash.html#index-read ).然后
read
实际上会读取该行,但它会返回一个非零状态(参考: https : //www.gnu.org/software/bash/manual/bash.html#index-read )。 This non-zero status causes the while
loop to end.此非零状态导致
while
循环结束。
The idiomatic way to handle this is:处理这个的惯用方法是:
while IFS= read -r list || [[ -n $list ]]; do
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