I have a pretty simple question:
exec('split -d -l 10 _.txt part');
This splits my _.txt file into chunks part00,part01 etc.
Can i set file extension for these chunks somehow?
Thank you,
It is possible by using the --filter option as documented in info coreutils 'split invocation':
split -d -l 10 _.txt part --filter='cat > $FILE.txt'
This will create part00.txt, part01.txt and so on. Also seems to work for binary files (with -b instead of -l).
# touch xaa xab xac; for f in xa{a..c};do echo mv -- "$f" "$f.txt";done
Related
I have a file called files.txt and I need to split it based on lines. The command is as follows -
split -l 1 files.txt file --numeric-suffixes=1 --suffix-length=4
The numeric suffixes here start from file0001 to file9000. But I want it to be from 1 to 9000.
I can't seem to change it when --suffix-length=1, as split exhausted output filenames. Any suggestions using the same split command?
I don't think split will do what you want it to do, though I'm on macOS, so the *nix I'm using is Darwin not Linux; however, a simple shell script would do the trick:
#!/bin/bash
N=1
cat $1 | while read line
do
echo "$line" > file$N
N=`expr $N + 1`
done
Assuming you save it as mysplit (don't forget chmod -x mysplit), then you run it:
./mysplit files.txt
Trying to figure out how to iterate through a .txt file (filemappings.txt) line by line, then split each line using tab(\t) as a delimiter so that we can create the directory specified on the right of the tab (mkdir -p).
Reading filemappings.txt and then splitting each line by tab
server/ /client/app/
server/a/ /client/app/a/
server/b/ /client/app/b/
Would turn into
mkdir -p /client/app/
mkdir -p /client/app/a/
mkdir -p /client/app/b/
Would xargs be a good option? Why or why not?
cut -f 2 filemappings.txt | tr '\n' '\0' | xargs -0 mkdir -p
xargs -0 is great for vector operations.
You already have an answer telling you how to use xargs. In my experience xargs is useful when you want to run a simple command on a list of arguments that are easy to retrieve. In your example, xargs will do nicelly. However, if you want to do something more complicated than run a simple command, you may want to use a while loop:
while IFS=$'\t' read -r a b
do
mkdir -p "$b"
done <filemappings.txt
In this special case, read a b will read two arguments separated by the defined IFS and put each in a different variable. If you are a one-liner lover, you may also do:
while IFS=$'\t' read -r a b; do mkdir -p "$b"; done <filemappings.txt
In this way you may read multiple arguments to apply to any series of commands; something that xargs is not well suited to do.
Using read -r will read a line literally regardless of any backslashes in it, in case you need to read a line with backslashes.
Also note that some operating systems may allow tabs as part of a file or directory name. That would break the use of the tab as the separator of arguments.
As others have pointed out, \t character could also be a part of the file or directory name, and the following command may fail. Assuming the question represents the true form of the input file, one can use:
$ grep -o -P '(?<=\t).*' filemappings.txt | xargs -d'\n' mkdir -p
It uses -P perl-style regex to get words after the \t(TAB) character, then use -d'\n' which provides all relevant lines as a single input to mkdir -p.
sed -n '/\t/{s:^.*\t\t*:mkdir -p ":;s:$:":;p}' filemappings.txt | bash
sed -n: only work with lines that contains tab (delimiter)
s:^.*\t\t*:mkdir -p :: change all things from line beggning to tab to mkdir -p
| bash: tell bash to create folders
With GNU Parallel it looks like this:
parallel --colsep '\t' mkdir -p {2} < filemapping.txt
I have a number of files with the following naming:
name1.name2.s01.ep01.RANDOMWORD.mp4
name1.name2.s01.ep02.RANDOMWORD.mp4
name1.name2.s01.ep03.RANDOMWORD.mp4
I need to remove everything between the last . and ep# from the file names and only have name1.name2.s01.ep01.mp4 (sometimes the extension can be different)
name1.name2.s01.ep01.mp4
name1.name2.s01.ep02.mp4
name1.name2.s01.ep03.mp4
This is a simpler version of #Jesse's [answer]
for file in /path/to/base_folder/* #Globbing to get the files
do
epno=${file#*.ep}
mv "$file" "${file%.ep*}."ep${epno%%.*}".${file##*.}"
#For the renaming part,see the note below
done
Note : Didn't get a grab of shell parameter expansion yet ? Check [ this ].
Using Linux string manipulation (refer: http://www.tldp.org/LDP/abs/html/string-manipulation.html) you could achieve like so:
You need to do per file-extension type.
for file in <directory>/*
do
name=${file}
firstchar="${name:0:1}"
extension=${name##${firstchar}*.}
lastchar=$(echo ${name} | tail -c 2)
strip1=${name%.*$lastchar}
lastchar=$(echo ${strip1} | tail -c 2)
strip2=${strip1%.*$lastchar}
mv $name "${strip2}.${extension}"
done
You can use rename (you may need to install it). But it works like sed on filenames.
As an example
$ for i in `seq 3`; do touch "name1.name2.s01.ep0$i.RANDOMWORD.txt"; done
$ ls -l
name1.name2.s01.ep01.RANDOMWORD.txt
name1.name2.s01.ep02.RANDOMWORD.txt
name1.name2.s01.ep03.RANDOMWORD.txt
$ rename 's/(name1.name2.s01.ep\d{2})\..*(.txt)$/$1$2/' name1.name2.s01.ep0*
$ ls -l
name1.name2.s01.ep01.txt
name1.name2.s01.ep02.txt
name1.name2.s01.ep03.txt
Where this expression matches your filenames, and using two capture groups so that the $1$2 in the replacement operation are the parts outside the "RANDOMWORD"
(name1.name2.s01.ep\d{2})\..*(.txt)$
I need a shell script to open latest text file from a given directory. it will be then copied to another directory. How can i achieve it?
I need a logic which will search and give the latest file from a directory (name of the text file can be anything (not fixed), so i need to find out latest text file)
Here you can do something like this
#!/bin/sh
SOURCE_DIR=/home/juned/Downloads
DEST_DIR=/tmp/
LAST_MODIFIED_FILE=`ls -t ${SOURCE_DIR}| head -1`
echo $LAST_MODIFIED_FILE
#Open file
vim $SOURCE_DIR/$LAST_MODIFIED_FILE
#Copy file
cp $SOURCE_DIR/$LAST_MODIFIED_FILE $DEST_DIR
echo "File copied successfully"
You can specify any application name in which you want to open that file like gedit, kate etc. Here I've used vim.
xdg-open - opens a file or URL in the user's preferred application
Not an expert in bash but you can try this logic:
First, grab the latest file using ls -t -t sorts by time head -1 gets the first file
F=`ls -t * | head -1`
Then open the file using and editor:
xdg-open $F
gedit $F
...
As suggested by # AJefferiss you can directly do :
xdg-open $(ls -t * | head -1)
gedit $(ls -t * | head -1)
For editing the latest modified / created,
vim $(ls -t | head -1)
For editing the latest in alphanumerical order,
vim $(ls -1 | tail -1)
In one line (if are you sure that there are only files):
vim `ls -t .|head -1`
it will be opened in vim (or use other txt editor)
if there are directories you should write script with loop and test every file (if it's not a dir):
if [ -f $FILE ];
or you can also use find, or use pipe for get latest file:
ls -lt .|sed -n 2p|grep -v '^d'
The existing answers are helpful, but fall short when it comes to dealing with filenames with embedded spaces or other shell metacharacters.[1]
# Get the most recently modified *.txt file.
# (On *assignment*, names with spaces, ... are not a concern.)
f=$(ls -t *.txt | head -n 1)
# *Use* the variable enclosed in *double-quotes* to ensure that it is passed
# to the target command unmodified.
xdg-open "$f" # could also use "$(ls -t *.txt | head -n 1)" directly
Additionally, some answer user all-uppercase shell variable names, which should be avoided so as to avoid conflicts with environment variables.
[1] Due to use of ls, filenames with embedded newlines won't be handled correctly, but that's rarely a real-world concern.
I want to tail multiple files (and follow them) in CentOS, I've tried this:
tail -f file1 file2 file3
but the output is very unfriendly
I've also had a look at multitail but can't find a CentOS version.
What other choices do I have?
Multitail is available for CentOS in rpmforge repos. To add rpmforge repository check the documentation on 3rd Party Repositories.
I found the solution described here work well on centos:
The link is http://www.thegeekstuff.com/2009/09/multitail-to-view-tail-f-output-of-multiple-log-files-in-one-terminal/
Thanks to Ramesh Natarajan
$ vi multi-tail.sh
#!/bin/sh
# When this exits, exit all back ground process also.
trap 'kill $(jobs -p)' EXIT
# iterate through the each given file names,
for file in "$#"
do
# show tails of each in background.
tail -f $file &
done
# wait .. until CTRL+C
wait
You could simulate multitail by opening multiple instances of tail -f in Emacs subwindows.
I usually just open another xterm and run a separate 'tail -f' there.
Otherwise if I'm using the 'screen' tool, I'll set up separate 'tail -f' commands there. I don't like that as much because it takes a few keystrokes to enable scrolling in screen before using the Page Up and Page Down keys. I prefer to just use xterm's scroll bar.
You can use the watch command, i use it to tail two files at the same time:
watch -n0 tail -n30 file1 file2
A better answer to an old question...
I create a shell function in my .bashrc (obviously assumes you're using bash as your shell) and use tmux. You can probably complicate this a whole lot and do it without the tempfile, but the quoting is just ugly if you're trying to ensure that files with spaces or other weird characters in the name still work.
multitail ()
{
cmdfile=`mktemp`
echo "new-session -d \"tail -f '$1'\"" >$cmdfile
shift
for file in "$#"
do
echo "split-window -d \"tail -f '$file'\"" >>$cmdfile
done
echo "select-layout even-vertical" >>$cmdfile
tmux source-file $cmdfile \; attach && rm -f $cmdfile
}