Here are some quick and easy bash commands to solve every day problems I run into. Comment and leave some of your own if you like. I might update this post with new ones over time. These are just some common ones.
Iterate through directory listing and remove the file extension from each file
ls -1 | while read each; do new=`echo $each |sed 's/\(.*\)\..*/\1/'` && echo $new && mv "$each" "$new"; done
Output relevant process info, and nothing else
ps axo "user,pid,ppid,%cpu,%mem,tty,stime,state,command"| grep -v "grep" | grep $your-string-here
Setup a SOCKS5 proxy on localhost port 5050, to tunnel all traffic through a destination server
ssh -N -D 5050 username@destination_server'
Setup a SOCKS5 proxy via a remote TOR connection, using local port 5050 and remote TOR port 9050
ssh -L 5050:127.0.0.1:9050 username@destination_server'
Display text or code file contents to screen but don't display any # comment lines
sed -e '/^#/d' $1 < $file_name_here
Same as above but replacing # lines with blank lines
sed -e '/^#/g' $1 < $file_name_here
Find all symlinks in the current directory and subdirs
find ./ -type l -exec ls -l {} \;
Find all executable files in current directory and subdirs
find ./ -type f -perm -o+rx -exec ls -ld '{}' \;
Remove all files matching the input string
echo -n "filename match to remove [rm -i]: " && read f; find ./ -name ${f} -exec rm -i {} \;
Display largest ten files in current dir and subdirs
du -a ./ | sort -n -r | head -n 10
Display all files in current dir and subdirs in order of filesize
du -a ./ | sort -n -r
Generate a MD5 hash for the input string (not file)
Linux: echo -n "str: " && read x && echo -n "$x" | md5sum
OSX: echo -n "str: " && read x && echo -n "$x" | md5
Display a summary of all files in current and subdirs
for t in files links directories; do echo `find . -type ${t:0:1} | wc -l` $t; done 2> /dev/null
Download a website's SSL Certificate to a file for later use
openssl s_client -showcerts -connect $HOST:443 > $FILE-NAME.txt
