tail: similar to head except prints the last 10(default) lines of a file. Hi, Before moving the files from source directory to target directory I need to check if the files have these strings 'Error', 'Not Valid' ,' YTF-' or if the file is a zero byte file, if the file contains these strings or if it is a zero byte file i should log a entry in the log file and fail.Never print headers giving file names -v, -verbose Print the first N lines instead of the first 10 with the leading `-', print all but the last N lines of each file -q, -quiet, -silent Print the first N bytes of each file with the leading `-',print all but the last N bytes of each file -n, -lines=N head: displays the first 10(default) lines of a file.See: Howto use the less command Commands for displaying parts of files It also uses page up and page down, and many other functions like searching. Another way to do this, although a less obvious way and probably less readable in a shell script by. This command makes sense as it is using standard UNIX redirection to place the contents of one file (a known empty one) to another file. less: is like more but allows you to go up and down in the file. To replace the contents of the file blah.txt with nothing, you can use the command.If the file is more than a page, it waits and allows you to scroll down the page with the down arrow key. Hint: shift-page up and shift-page down allow you to page up and down in you terminal, so you can view previous output If the contents of your file is larger than a page, cat will not stop paging through the program until it hits the end cat command: print all the contents of the file in terminal.2 Commands for displaying parts of files.Binary prefixes can be used, too: KiB=K, MiB=M, and so on. Units are K,M,G,T,P,E,Z,Y (powers of 1024) or KB,MB.
The advantage of that, is that du can accept an argument to that option in a known format - either human as in 10K, 10MiB or what ever you feel comfortable with - you don't need to manually convert between formats / units since du handles that.įor reference, here's the explanation on this SIZE argument from the man page: The SIZE argument is an integer and optional unit (example: 10K isġ0*1024). touch command is used to create the empty or zero byte file,touch command also used to update the access or modification time of the file.touch command is basically used to create multiple files in linux or ing Cat command one can create or update one file at a time but using touch command user can only create multiple zero byte files. Mv -f /root/tmp/file.txt /var/www/file.txt
Here's my solution, using du -threshold= for OP's use case: THRESHOLD=90k Quoting from du(1)'s manual: -t, -threshold=SIZEĮxclude entries smaller than SIZE if positive, or entries greater
Not sure if this option is available in all versions of du but it is implemented in GNU's version. On Linux, you'd start with something like stat -c '%s' file.txt, and on BSD and Mac OS X, something like stat -f '%z' file.txt. If you need more control over the output format, you can also look at stat.
In this case, it sounds like that's what you want.īut FYI, if you want to know how much disk space the file is using, you could use du -k to get the size (disk space used) in kilobytes: file=file.txtĮcho size is under $minimumsize kilobytes
zip -size 0c This command not only lists the 0 byte files within dorectory A, but also lists the 0 byte files within directory B. The problem: I only need to find out the names of the 0 byte files in the directory A. To get a file's size, you can use wc -c to get the size (file length) in bytes: file=file.txt This directory also has a subdirectory B which also has some 0 byte files in it. If you want to say "size is non-zero", you need. It checks that the string file.txt is non-zero length, so it will always succeed.