Editing Linux

;Copy directories without content
<pre>
rsync -av -f"+ */" -f"- *" "$source" "$target"
</pre>
;Find files
 find /path/to/dir -type f -name "*" -newermt 2013-02-07 ! -newermt 2013-02-08
 find $HOME/projects -type f -name "*.py" -newermt 2013-02-07 ! -newermt 2013-02-08 -print
 find $HOME/projects -type f -name "*.py" -newermt 2013-02-07 ! -newermt 2013-02-08 -ls
;Delete Files older Than
<pre>
find /var/log -name "*.log" -type f -mtime +30 -delete 
find /var/log -type d -mtime +30 -exec rm -rf {} \;
</pre>
;How to print a file, excluding comments and blank lines, using grep
<pre>grep -v '^$\|^#\|^\s*\#' filename | grep -v "^[[:space:]]*$" | more
grep -v "^[[:space:]]*$\|^ *#" filename 
</pre>
;bash operations with file with spaces in name
 IFS=$(echo -en "\n\b"); for i in $(ls -d */ | cut -f1 -d'/'); do echo $i; done
 IFS=$(echo -en "\n\b"); for i in $(ls -d */ | cut -f1 -d'/'); do echo "$i;"| tr -d '\r\n'; find $i -type f | wc -l; done
;ssh automation
 ssh -i /usr/local/sbin/id_rsa -oStrictHostKeyChecking=no ansible@10.0.0.26 'upsc qnapups'
 -i RSA key, -o add to known host automatically
; ls with full path
 ls -dl $PWD/*

;Set date of directories by latest file inside
 IFS=$(echo -en "\n\b"); for d in */ ; do T=`ls -alt --time-style="+%Y%m%d0101.10" $d | tail -1 | awk '{print $6}'`; touch -t $T $d; done

;Частотный анализ букв в именах файлов
 ls | awk '{for (i=1 ; i<=NF ; i++) array[$i]++ } END{ for (char in array) print char,array[char]}' FS="" | sort -k2 -n

;Find and replace characters in file name
 for file in `IFS=$(echo -en "\n\b"); find . -name "*[+]*" `; do mv -v $file $(echo $file | sed -e 's/+//g'); done

;Rename bulk of files by template
 for file in *_AV1.mkv; do mv "$file" "${file%_AV1.mkv}.av1"; done

;[[Audiofile operations]]
;[[Photo file operations]]
;[[LVM operations]]
;[[SSL Certificate with SAN]]
;[[SSL Certificate signed by your own CA]]
;[[SD card partition recovery]]
;[[How to recreate a wiped /boot filesystem in Ubuntu]]