Unix commands

This is mostly just a post for my recollection. To search all files and subdirectories recursively for a phrase:

grep -r -i somethingtosearchfor ./

Delete files older than 7 days
find . -type f -mtime +7 -exec rm -rf {} \;
 find . -daystart -maxdepth 1 -type f -mtime +7 -exec echo rm {} \; (echo before submitting, and doesn't remove files in sub directories).

Delete files following a certain pattern
find -name "3j*" -exec rm -rf {} \;

Return to previous directory

for linux if u want to return to previous directory u can type.
eg:

$ cd -

Count Files in current directory:
 ls  -l | awk '!/^d/{print }' | wc -l

Find specific files and replace string:
find -type f -name pom.xml|xargs sed -i 's/4.5.1/4.6.0/g'
grep --include 'pom.xml' -rn 4.5.1 .

 grep --include 'pom.xml' -rn 4.6.0 .

sha256sum

sha256sum ubuntu-9.10-dvd-i386.iso

Find IP Mac:

ifconfig | grep "inet " | grep -Fv 127.0.0.1 | awk '{print $2}' 

Create user and add to sudo group:

   42  sudo adduser 
   43  sudo adduser solis-user
   44  sudo usermod
   45  sudo usermod -aG sudo solis-user