Questions tagged [truncate]
19 questions
283
votes
3 answers
Most efficient method to empty the contents of a file
I am aware of three methods to delete all entries from a file.
They are
>filename
touch filename1
filename < /dev/null
Of these three I abuse >filename the most as that requires the least number of keystrokes.
However, I would like to know which…
debal
- 3,664
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24
votes
4 answers
Is there any limit on line length when pasting to a terminal in Linux?
I am trying to send messages from kafka-console-producer.sh, which is
#!/bin/bash
if [ "x$KAFKA_HEAP_OPTS" = "x" ]; then
export KAFKA_HEAP_OPTS="-Xmx512M"
fi
exec $(dirname $0)/kafka-run-class.sh kafka.tools.ConsoleProducer "$@"
I am pasting…
Dims
- 3,181
- 9
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6
votes
9 answers
Is it possible to truncate a file (in place, same inode) at the beginning?
It is possible to remove trailing bytes of a file without writting to a new file (> newfile) and moving it back (mv newfile file). That is done with truncate:
truncate -s -1 file
It is possible to remove leading bytes but by moving it around (which…
user232326
4
votes
1 answer
Difference between writing file from /dev/zero and truncate
$ timeout 1 cat /dev/zero > file1
$ wc -c file1
270422016 file1
$ du file1
264084 file1
Questions :
(1) How do 270422016 null characters come out to be 264084 bytes (i.e 258M).
$ truncate -s 270422016 file2
$ wc -c file2
270422016 file2
$ du…
GypsyCosmonaut
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2
votes
1 answer
Truncate file that is opened in another procces
If I try truncate -s 0 log.log (:>log.log has same behavior) the displayd space on disk do become free but the size (ls -l) of file is still the same (tho du shows less). As far as I understand, it happens because the pointer is still "old".
This…
Sova
- 23
- 2
2
votes
2 answers
/usr/bin/truncate: Argument list too long
I want to use the truncate command to create a huge number of small files for testing. I tried the command with a small number of files (100) and it worked. When I changed the number to 1000000, it reports an error:
root:[~/data]# truncate -s 1k…
Just a learner
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1
vote
0 answers
truncate command to to safely remove Celery log files?
I my Ubuntu server that is running Python/Celery has about 9 log files totaling to 9GB space.
Is it safe to reduce the size of these files by running the following command?
truncate -s 0 *log
If not, is there any other suggestions to reduce the…
user1761583
- 11
- 2
1
vote
1 answer
tee pipeline and pnmtools - truncated file
This sequence of commands works OK:
pngtopnm file.png 2> /dev/null > dump1
pnmfile < dump1
stdin: PPM raw, 1920 by 1080 maxval 255
ls -l dump1
-rw-r----- 1 cmb 6220817 Sep 15 14:26 dump1
But redoing the pipeline to use 'tee' truncates the output…
ColinB
- 113
- 3
1
vote
1 answer
ffmpeg truncates paths on output when there are dots involved when run on bash
If I have a path with dots in the path, for instance:
/home/user/Documents/hello/test.testing_23-24.123/test.testing_23-24.124
ffmpeg can locate the file if you pass the file's path as an argument but it will truncate the path name to the first dot…
sternumbeef
- 11
- 2
1
vote
1 answer
How to print multiple columns without truncating?
I know that pr -m -t file1 file2 will give me 2 columns like so:
file1:
a
abc
abcdefg
abcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyz
file2:
1
123
12345678
12345678901234567890
-
$ pr -m -t file1 file2
a 1
abc …
Timothy Swan
- 141
- 10
1
vote
1 answer
What size blocks does `truncate --io-blocks` use?
What size blocks does GNU truncate --io-blocks use?
-o, --io-blocks
treat SIZE as number of IO blocks instead of bytes
512 bytes
blockdev --getbsz
blockdev --getpbsz
Tom Hale
- 28,728
- 32
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0
votes
1 answer
Problem creating a disk image of an SD card
I have built a custom image of Armbian with a partition size of 3.1 GB, and I am now finished working with it. It is currently written to a bootable 64 GB SD card which is using a GUID partition table (GPT).
My problem is, is that when I want to…
Chris Hudlin
- 23
- 4
0
votes
0 answers
"> $logfile" does not truncate, file size goes to 0 and a second later, is back to full size
I have a script that writes to a logfile like this:
$ nohup myscript.sh > myscript.out 2>&1 &
when the log file gets very large, I need to truncate it like this:
> myscript.out
I see the size go to 0 briefly but immediately jumps back to full size…
chiwal
- 1
- 1
0
votes
1 answer
Truncate expand doesnt seem to work?
I just expanded my 1G "homefile" which is mounted to /home/user by another GB using truncate -s +1G homefile, and while it changed the size of homefile shown with df to 2GB, when mounted it is still only 1GB. Am I missing something? I dont have to…
alchemy
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0
votes
0 answers
truncate linux kernel
firstly sorry for my English.
I want to truncate kernel options like Bluetooth, mouse, keyboard etc.. except for my use.
but how can I know that kernel options related to devices that I want to remove?
I've been that work with "make…
Jinwoo Bae
- 13
- 4