Bash for loop array


 
Thread Tools Search this Thread
Top Forums Shell Programming and Scripting Bash for loop array
# 1  
Old 03-13-2018
Bash for loop array

Hi there,

A bit new to bash and am having an issue with a for loop. I look for filenames in a specified directory and pull the date string from each meeting a certain criteria, and then would like to make a directory for each date found, like this:

Code:
search 20180101.gz 20180102.gz 20180103.gz
store 20180101 20180102 20180103 in an array
mkdir for each value found

The problem is that the mkdir part is only making a directory for the first value found.

This is the actual code:

Code:
for line in $(echo ${DPPATH}/${DBNAME}*.dmp.gz ${MTIMECMD} -type f |grep -Eo '[[:digit:]]{8}')
do
find ${DPPATH}/${DBNAME}*.dmp.gz ${MTIMECMD} -type f -exec /usr/local/bin/aws s3 mv {} "s3://"${S3BUCKET}/export_area/${DBNAME}/${line}/ \;
done

Any input would be greatly appreciated.

Last edited by jim mcnamara; 03-13-2018 at 04:16 PM..
# 2  
Old 03-13-2018
Quote:
Originally Posted by mwheeler12
Code:
search 20180101.gz 20180102.gz 20180103.gz
store 20180101 20180102 20180103 in an array
mkdir for each value found

The problem is that the mkdir part is only making a directory for the first value found.
First off: you won't need an array at all, so is there any other reason (outside of you thinking you'd need one) for it?

If not: a for-loop gets a list of values and runs the loops body with each of it. Here is an example:

Code:
for LOOPVAR in first second third fourth ; do
     echo "LOOPVAR is: $LOOPVAR"
done

The loops body is the echo-statement here and as you can see the variable LOOPVAR is assigned one value after the other. You can not only use a static list to fill this variable but also a (so-called) "fileglob": a pattern with wildcards, which will be expanded to a list of filenames fitting this pattern:

Code:
for LOOPVAR in *dmp.gz ; do
     echo "LOOPVAR is: $LOOPVAR"
done

Run this in the right directory (i have ommitted pathes for readability) and you will see that LOOPVAR is assigned a list of filenames consecutively.

Now you are left with two tasks: first, create the directory name from the filename (if i have read your problem sttement correctly you want to create a directory "foo" for a file named "foo.dmp.gz" found, yes?) and secondly, replace the "echo"-command with the "mkdir"-command. It is always a good practice to first try such constructs with "echo" and only as the last step replace it with the real command.

For the change of the filename to the directory name we use "variable expansion" and you may want to read up upon it. It is a versatile device and you should know about it:

Code:
for FILENAME in *dmp.gz ; do
     echo "FILENAME is: $FILENAME, DIRNAME is: ${FILENAME%.dmp.gz}"
done

${variable%pattern} means: print the content of variable but omit an eventual pattern from the end of it: "foopattern" -> "foo".

We have all in place now, so we put in our mkdir command:

Code:
for FILENAME in *dmp.gz ; do
     mkdir "${FILENAME%.dmp.gz}"
done

That's it. In case you want to create the directory somewhere else:

Code:
for FILENAME in *dmp.gz ; do
     mkdir "/some/where/else/${FILENAME%.dmp.gz}"
done

I hope this helps.

bakunin
This User Gave Thanks to bakunin For This Post:
# 3  
Old 03-20-2018
Looping

Thanks bakunin, I appreciate the reply.

I am still having trouble getting the loop to work for each date pulled from the filename using this code:

Code:
for line in $(echo ${DPPATH}/${DBNAME}*.dmp.gz ${MTIMECMD} -type f |grep -Eo '[[:digit:]]{8}')
do
find ${DPPATH}/${DBNAME}*.dmp.gz ${MTIMECMD} -type f -exec /usr/local/bin/aws s3 mv {} "s3://"${S3BUCKET}/export_area/${DBNAME}/${line%}/ \;
done

My expectation is:
1. For each file (*.dmp.gz), pull the YYYYMMDD date older than MTIMECMD - this works.
2. For each date matching the criteria, execute /usr/local/bin/aws s3 mv command - this down not work. It does not 'break' from one filename date to the next:

Code:
+ echo /backup01/export_area/d1bebo/d1bebo_metadata_exp_schema_exp_01_20180312_1824.dmp.gz /backup01/export_area/d1bebo/d1bebo_metadata_exp_schema_exp_01_20180314_1130.dmp.gz -type f
+ find /backup01/export_area/d1bebo/d1bebo_metadata_exp_schema_exp_01_20180312_1824.dmp.gz /backup01/export_area/d1bebo/d1bebo_metadata_exp_schema_exp_01_20180314_1130.dmp.gz -type f -exec /usr/local/bin/aws s3 mv '{}' <path_removed>/20180312/ ';'
Completed 1 of 2 part(s) with 1 file(s) remaining
Completed 2 of 2 part(s) with 1 file(s) remaining
move: ./d1bebo_metadata_exp_schema_exp_01_20180312_1824.dmp.gz to <path_removed>/20180312/d1bebo_metadata_exp_schema_exp_01_20180312_1824.dmp.gz
Completed 1 of 2 part(s) with 1 file(s) remaining
Completed 2 of 2 part(s) with 1 file(s) remaining
move: ./d1bebo_metadata_exp_schema_exp_01_20180314_1130.dmp.gz to <path_removed>/20180312/d1bebo_metadata_exp_schema_exp_01_20180314_1130.dmp.gz
+ find '/backup01/export_area/d1bebo/d1bebo*.dmp.gz' -type f -exec /usr/local/bin/aws s3 mv '{}' <path_removed>/20180314/ ';'
find: ‘/backup01/export_area/d1bebo/d1bebo*.dmp.gz': No such file or directory

Here, I find 2 files. One dated 20180312 and one 20180314. The first file is moved to the 20180312 directory as expected, but then, the second file is also moved to that directory. The piece of code then tries to move the file dated 20180314 to the 20180314 directory, but can't find it since it has already been moved.

Any suggestions would be greatly appreciated. Thanks again for the help.
# 4  
Old 03-26-2018
Looking for a suggestion. Any input would be greatly appreciated. It is driving me nuts.
# 5  
Old 03-27-2018
Quote:
Originally Posted by mwheeler12
Thanks bakunin, I appreciate the reply.

I am still having trouble getting the loop to work for each date pulled from the filename using this code:

Code:
for line in $(echo ${DPPATH}/${DBNAME}*.dmp.gz ${MTIMECMD} -type f |grep -Eo '[[:digit:]]{8}')
do
find ${DPPATH}/${DBNAME}*.dmp.gz ${MTIMECMD} -type f -exec /usr/local/bin/aws s3 mv {} "s3://"${S3BUCKET}/export_area/${DBNAME}/${line%}/ \;
done

My expectation is:
1. For each file (*.dmp.gz), pull the YYYYMMDD date older than MTIMECMD - this works.
2. For each date matching the criteria, execute /usr/local/bin/aws s3 mv command - this down not work. It does not 'break' from one filename date to the next:

Code:
+ echo /backup01/export_area/d1bebo/d1bebo_metadata_exp_schema_exp_01_20180312_1824.dmp.gz /backup01/export_area/d1bebo/d1bebo_metadata_exp_schema_exp_01_20180314_1130.dmp.gz -type f
+ find /backup01/export_area/d1bebo/d1bebo_metadata_exp_schema_exp_01_20180312_1824.dmp.gz /backup01/export_area/d1bebo/d1bebo_metadata_exp_schema_exp_01_20180314_1130.dmp.gz -type f -exec /usr/local/bin/aws s3 mv '{}' <path_removed>/20180312/ ';'
Completed 1 of 2 part(s) with 1 file(s) remaining
Completed 2 of 2 part(s) with 1 file(s) remaining
move: ./d1bebo_metadata_exp_schema_exp_01_20180312_1824.dmp.gz to <path_removed>/20180312/d1bebo_metadata_exp_schema_exp_01_20180312_1824.dmp.gz
Completed 1 of 2 part(s) with 1 file(s) remaining
Completed 2 of 2 part(s) with 1 file(s) remaining
move: ./d1bebo_metadata_exp_schema_exp_01_20180314_1130.dmp.gz to <path_removed>/20180312/d1bebo_metadata_exp_schema_exp_01_20180314_1130.dmp.gz
+ find '/backup01/export_area/d1bebo/d1bebo*.dmp.gz' -type f -exec /usr/local/bin/aws s3 mv '{}' <path_removed>/20180314/ ';'
find: ‘/backup01/export_area/d1bebo/d1bebo*.dmp.gz': No such file or directory

Here, I find 2 files. One dated 20180312 and one 20180314. The first file is moved to the 20180312 directory as expected, but then, the second file is also moved to that directory. The piece of code then tries to move the file dated 20180314 to the 20180314 directory, but can't find it since it has already been moved.

Any suggestions would be greatly appreciated. Thanks again for the help.
From your trace output we can see that the variable MTIMECMD is either unset or set to an empty string. We, therefore, know that your statement:
Quote:
For each file (*.dmp.gz), pull the YYYYMMDD date older than MTIMECMD - this works.
is wrong. The values extracted by your for loop are in no way related to any date (since no date is specified by that variable). If MTIMECMD had been set to something like:
Code:
MTIMECMD="! -newer pathname"

where pathname is the pathname of a file you wanted to use to select gzipped dump files that are not newer than you want to select, you would still have the problem that the echo command in your for loop doesn't understand find primitives as a means to select parameters to be echoed. And, even if it did, as you have already found, there is nothing in your find command inside your for loop that makes any attempt to select files destined for a particular date from being selected to be moved to a different directory.

Maybe something more like the following would work better. Note, however, that the following is totally untested.

Code:
IAm=${0##*/}
tmpfile=$IAm.$$
DBNAME="something"
DPPATH="/what/ever"
MTIMECMD="! -newer /some/pathname"
S3BUCKET="who_knows"

trap 'rm -f "$tmpfile"' EXIT

for datestamp in $(find "$DPPATH" -name "/${DBNAME}*.dmp.gz" $MTIMECMD -type f | tee "$tmpfile" | grep -Eo '[[:digit:]]{8}' | sort -u)
do	# The following assumes that your aws command creates the needed datestamp directories for you.
	grep "$datestamp" "$tmpfile" | while IFS="" read -r path
	do	/usr/local/bin/aws s3 mv "$path" "s3://$S3BUCKET/export_area/$DBNAME/$datestamp/"
	done
done

This User Gave Thanks to Don Cragun For This Post:
# 6  
Old 03-27-2018
It works!

Thanks a lot. I changed it up a little to reformat the date. This is the complete solution:

Code:
for datestamp in $(find "$DPPATH" -name "${DBNAME}*.dmp.gz" $MTIMECMD -type f | tee "$tmpfile" | grep -Eo '[[:digit:]]{8}' | sort -u)
do
        grep "$datestamp" "$tmpfile" | while IFS="" read -r path
        do /usr/local/bin/aws s3 mv "$path" "s3://$S3BUCKET/export_area/$DBNAME/${datestamp:0:4}-${datestamp:4:2}-${datestamp:6:2}/"
        done
done

Thanks again.
Login or Register to Ask a Question

Previous Thread | Next Thread

10 More Discussions You Might Find Interesting

1. Shell Programming and Scripting

Bash Array connectin to another Array

Hello, i have a script that i need account_number to match a name. for exsample : ACCOUNT_ID=(IatHG8DC7mZbdymSoOr11w KbnlG2j-KRQ0-1_Xk356s8) and i run a loop curl requst with this the issue is that i want to know on which account were talking about so bash will know this : ... (4 Replies)
Discussion started by: batchenr
4 Replies

2. UNIX for Beginners Questions & Answers

Bash array variables are changed in loop runtime

I am trying to check whether particular host and port are responding or not. I am using below script to check. but node_port array that i am using in loop is getting replaced with previous iteration value. Script and output is given. Please help me to understanding why node_port values are... (5 Replies)
Discussion started by: tmalik79
5 Replies

3. Shell Programming and Scripting

Bash arrays: rebin/interpolate smaller array to large array

hello, i need a bit of help on how to do this effectively in bash without a lot of extra looping or massive switch/case i have a long array of M elements and a short array of N elements, so M > N always. M is not a multiple of N. for case 1, I want to stretch N to fit M arrayHuge H = (... (2 Replies)
Discussion started by: f77hack
2 Replies

4. Shell Programming and Scripting

Bash - array loop performance

Hi, another little question... "sn" is an array whose elements can vary from about 55,000 to about 150,000 elements. Each element consists of an integer between 0-255, eg: ${sn} contain the value: 103 . For a decrypt-procedure I need scroll all the elements 4 or 5 times. Here is an example of... (15 Replies)
Discussion started by: math4
15 Replies

5. Shell Programming and Scripting

awk loop using array:wish to store array values from loop for use outside loop

Here's my code: awk -F '' 'NR==FNR { if (/time/ && $5>10) A=$2" "$3":"$4":"($5-01) else if (/time/ && $5<01) A=$2" "$3":"$4-01":"(59-$5) else if (/time/ && $5<=10) A=$2" "$3":"$4":0"($5-01) else if (/close/) { B=0 n1=n2; ... (2 Replies)
Discussion started by: klane
2 Replies

6. Shell Programming and Scripting

Bash 3.2 - Array / Regex - IF 3rd member in array ends in 5 digits then do somthing...

Trying to do some control flow parsing based on the index postion of an array member. Here is the pseudo code I am trying to write in (preferably in pure bash) where possible. I am thinking regex with do the trick, but need a little help. pesudo code if == ENDSINFIVEINTS ]]; then do... (4 Replies)
Discussion started by: briandanielz
4 Replies

7. Shell Programming and Scripting

Array Variable being Assigned Values in Loop, But Gone when Loop Completes???

Hello All, Maybe I'm Missing something here but I have NOOO idea what the heck is going on with this....? I have a Variable that contains a PATTERN of what I'm considering "Illegal Characters". So what I'm doing is looping through a string containing some of these "Illegal Characters". Now... (5 Replies)
Discussion started by: mrm5102
5 Replies

8. Shell Programming and Scripting

problem access array outside of loop in bash

Below is a test script I was trying to use so that I could understand why the logic was not working in a larger script. While accessing and printing array data inside the while loop, everything is fine. Outside the loop, i guess everything is null?? The for loop that is meant to cycle... (4 Replies)
Discussion started by: adlmostwanted
4 Replies

9. Shell Programming and Scripting

Using variables created sequentially in a loop while still inside of the loop [bash]

I'm trying to understand if it's possible to create a set of variables that are numbered based on another variable (using eval) in a loop, and then call on it before the loop ends. As an example I've written a script called question (The fist command is to show what is the contents of the... (2 Replies)
Discussion started by: DeCoTwc
2 Replies

10. Shell Programming and Scripting

bash and ksh: variable lost in loop in bash?

Hi, I use AIX (ksh) and Linux (bash) servers. I'm trying to do scripts to will run in both ksh and bash, and most of the time it works. But this time I don't get it in bash (I'm more familar in ksh). The goal of my script if to read a "config file" (like "ini" file), and make various report.... (2 Replies)
Discussion started by: estienne
2 Replies
Login or Register to Ask a Question