I have a list of files that I need to pipe into a shell script. I can list the files within a directory by using the following:
ls ~/data/2121/*SOMEFILE*
resulting in:
2121.SOMEFILEaa
2121.SOMEFILEab
2121.SOMEFILEac
and so on...
I have another script that performs some processing on a single file (2121.SOMEFILEaa) which I run by using the following command:
bash runscript ../data/2121/2121.SOMEFILEaa
However, I need to make this more efficient by piping individual files from the list of files generated via ls into the script. How can I pipe the results from the ls ~/data/2121/*SOMEFILES* command--file by file--into the runscript script?
Another option
ls ~/data/2121/*SOMEFILE* | xargs -L1 bash runscript
I think you are looking for this:
for file in ~/data/2121/*SOMEFILE*; do
bash runscript "$file"
done
In this way, you're calling bash runscript for each file.
$ cat pipe.sh
#!/bin/bash
## Store data from pipe to variable $PIPE ------#
_read_pipe(){ #
while read -t 10 pipe; do
if [ -n "$pipe" ] ;then
PIPE="$PIPE $pipe" ;fi ;done ;}
## your code -----------------------------------#
_read_pipe #
for kung_foo in $PIPE ;do
echo $kung_foo ;done
$ ls 2121.SOMEFILE* | ./pipe.sh
2121.SOMEFILEaa
2121.SOMEFILEab
2121.SOMEFILEac
and so on...
[ -t ] is for timeout
I hope this helps,
cheers Karim
Related
So guys,
I need your help trying to identify the fastest and the most "fault" tolerant solution to my problem.
I have a shell script which executes some functions, based on a txt file, in which I have a list of files.
The list can contain from 1 file to X files.
What I would like to do is iterate over the content of the file and execute my scripts for only 4 items out of the file.
Once the functions have been executed for these 4 files, go over to the next 4 .... and keep on doing so until all the files from the list have been "processed".
My code so far is as follows.
#!/bin/bash
number_of_files_in_folder=$(cat list.txt | wc -l)
max_number_of_files_to_process=4
Translated_files=/home/german_translated_files/
while IFS= read -r files
do
while [[ $number_of_files_in_folder -gt 0 ]]; do
i=1
while [[ $i -le $max_number_of_files_to_process ]]; do
my_first_function "$files" & # I execute my translation function for each file, as it can only perform 1 file per execution
find /home/german_translator/ -name '*.logs' -exec mv {} $Translated_files \; # As there will be several files generated, I have them copied to another folder
sed -i "/$files/d" list.txt # We remove the processed file from within our list.txt file.
my_second_function # Without parameters as it will process all the files copied at step 2.
done
# here, I want to have all the files processed and don't stop after the first iteration
done
done < list.txt
Unfortunately, as I am not quite good at shell scripting, I do not know how to structure it so that it won't waste any resources and mostly, to make sure that it "processes" everything from that file.
Do you have any advice on how to achieve what I am trying to achieve?
only 4 items out of the file. Once the functions have been executed for these 4 files, go over to the next 4
Seems to be quite easy with xargs.
your_function() {
echo "Do something with $1 $2 $3 $4"
}
export -f your_function
xargs -d '\n' -n 4 bash -c 'your_function "$#"' _ < list.txt
xargs -d '\n' for each line
-n 4 take for arguments
bash .... - run this command with 4 arguments
_ - the syntax is bash -c <script> $0 $1 $2 etc..., see man bash.
"$#" - forward arguments
export -f your_function - export your function to environment so child bash can pick it up.
I execute my translation function for each file
So you execute your translation function for each file, not for each 4 files. If the "translation function" is really for each file with no inter-file state, consider rather executing 4 processes in parallel with same code and just xargs -P 4.
If you have GNU Parallel it looks something like this:
doit() {
my_first_function "$1"
my_first_function "$2"
my_first_function "$3"
my_first_function "$4"
my_second_function "$1" "$2" "$3" "$4"
}
export -f doit
cat list.txt | parallel -n4 doit
I wrote a small script which:
prints the content of a file (generated by another application) on paper with a matrix printer
prints the same line into a backup file
removes the original file.
The script runs every minute by a cronjob and works fine as long as there are files to print. If there are no files to print, it prints an empty line on the matrix printer and in the backup file. I don't understand why this happens as i implemented an if statement which checks if there is a file to print before the print command is executed. This behaviour only happens if the script is executed by the cron and not if i execute it manually with ./script.sh. What's the reason of this? and how can i solve it?
Something i noticed on the side is that if I place an echo "hi" command in the script, its printed to the matrix printer and the backup file. I expected that its printed to the console console when it has no >> something behind. How does this work?
The script:
#!/bin/bash
# Make sure the backup directory exists
if [ ! -d /home/user/backup_logprint ]
then
mkdir /home/user/backup_logprint
fi
# Print the records if there are any
date=`date +%Y-%m-%d`
filename='_logprint_backup'
printer_path="/dev/usb/lp0"
if [ `ls /tmp/ | grep logprint | wc -l` -gt 0 ]
then
for f in `ls /tmp | grep logprint`
do
echo `cat /tmp/$f` >> "/home/user/backup_logprint/$date$filename"
echo `cat /tmp/$f` >> $printer_path
rm "/tmp/$f"
done
fi
There's no need for ls or an if statement. Just use a proper glob in the for loop, and if no file match, the loop won't be entered.
#!/bin/bash
# Don't check first; just let mkdir decide if
# anything actually needs to be created.
d=/home/user/backup_logprint
mkdir -p "$d"
filename=$(date +"$d/%Y-%m-%d_logprint_backup")
printer_path="/dev/usb/lp0"
# Cause non-matching globs to expand to an empty
# sequence instead of being treated literally.
shopt -s nullglob
for f in /tmp/*logprint*; do
cat "$f" > "$printer_path" && mv "$f" "$d"
done
I am trying to make a script what looks at a folder and will automatically encode files that go into that folder using hand brake. I want to do this doing monitoring the folder using inotify putting the new additions to the folder into a list then using a cron job to encode them overnight. However when using a while loop to loop over the list handbrake only encodes the first file exists then the scripts carrys on to after the loop without doing every file in the list. Here is the script that is calling handbrake:
#!/bin/bash
while IFS= read -r line
do
echo "$(basename "$line")"
HandBrakeCLI -Z "Very Fast 1080p30" -i "$line" -o "$line.m4v"
rm "$line"
done < list.txt
> list.txt
When testing the loop with a simple echo instead of the HandBrakeCLI it works fine and prints out every file so I have no idea what is wrong.
Here is the scripts that is monitoring the folder incase that is the problem:
#!/bin/bash
if ! [ -f list.txt ]
then
touch list.txt
fi
inotifywait -m -e create --format "%w%f" tv-shows | while read FILE
do
echo "$FILE" >> list.txt
done
Any help would be great, thanks
EDIT:
Just to be more specific, the script works fine for the first file in the list.txt, it encodes it no problem and removes the old version, but then it doesn't do any of the others in the list
Taken from here
To solve the problem simply
echo "" | HandBrakeCLI ......
or
HandBrakeCLI ...... < /dev/null
I'm trying to have a command that will print only the non-executable files sorted by modification time in the current directory.
What I have so far is:
$ ls -lt | grep -i "...x......"
This is printing all of the files in the dir. Just starting to learn code, any help would be much appreciated.
The way to go :
for file in *; do test -x "$file" || echo "$file"; done
Thanks to not parsing ls output
How can I list the path of the output of this script?
This is my command:
(ls -d */ ); echo -n $i; ls -R $i | grep "wp-config.php" ;
This is my current output:
/wp-config.php
It seems you want find the path to a file called "wp-config.php".
Does the following help?
find $PWD -name 'wp-config.php'
Your script is kind of confusing: Why does ls -d */ does not show any output? What's the value of $i? Your problem in fact seems to be that ls -R lists the contents of all subdirectories but doesn't give you full paths for their contents.
Well, find is the best tool for that, but you can simulate it in this case via a script like this:
#!/bin/bash
searchFor=wp-config.php
startDir=${1:-.}
lsSubDir() {
local actDir="$1"
for entry in $(ls "$actDir"); do
if [ -d "$actDir/$entry" ]; then
lsSubDir "$actDir/$entry"
else
[ $entry = $searchFor ] && echo "$actDir/$entry"
fi
done
}
lsSubDir $startDir
Save it in a file like findSimulator, make it executable and call it with the directory where to start searching as parameter.
Be warned: this script is not very efficient, it may stop on large subdirectory-trees because of recursion. I would strongly recommend the solution using find.