Terminal Commands for Mac OS

this is a long and useful list of all the terminal Mac commands i frequently use

Customize your Terminal Bash Prompt

Before you begin your terminal ways, you can make your bash prompt on the terminal look fancy.I love tweaking the way my prompt looks and these are the settings I use:

Check your current Bash Prompt paramters
```
echo $PS1
default is \h:\W \u\$  
```

Now the Terminal commands in increasing order of geek-pleasure:

File Commands

remember at any point to quit command and return to prompt hit Ctrl + C

Change Directory
```
cd <directory you want to change to>
```
Show Present directory
```
pwd
```
Make Directory
```
mkdir <name of directory you want>
```

File Listing

File Listing Basic
```
ls -al
```
File Listing with more details
```
ls -altr
```

Open File

open -a <Name of Application> <filename>
open -a Fraise todo.txt

Deleting

delete file
```
rm <filename>
```
delete directory
```
rm -r <directory name>
```
forcefully delete
```
rm -f <filename>
```
example : remove all pesky DS_Store
```
rm -rvf '.DS_Store'
```
Copying File1 to File2
```
cp <file1> <file2>
```
Rename File1 to File2
```
mv <file1> <file2>
```
Create Symbolic Link
```
ln -s <filename> <linkname>
```

output contents of file

more <filename>
less <filename>
head <filename>
tail <filename>

show the last lines as they grow
```
tail -f <filename></ul> 
```

Searching

Find all instances of a file
```
locate <filename>
```
File Finding Advanced
```
find /Applications -name "*.ttf"
```

the famous grep searcher

grep <pattern> <files> <command> | grep <pattern>

recursively grep through directories
```
grep -r <pattern> <directoryname> 
```
Find an application
```
whereis <application name>
```
which is the default application that will run
```
which  <application name>
```

Compairson Commands

Find the differences between two folders

diff -rq /Users/kaushikgopal/Music /Volumes/Storage/Music

Process Management

Display currently active processes
```
    ps  
    ps aux
```

Terminate or kill a process

    kill <pid>
    killall <process name>

sequence of commands to relaunch the Finder App

    ps | grep Finder (get PID)
    kill PID
    open /System/Library/CoreServices/Finder.app

rsync and the world of Synchronization

rsync deserves a post of it’s own, but to give you a brief idea, here are a couple of commands i use frequently:

Synchronize Music Storage folders on Macbook and External Drive
```
    rsync -av --progress --size-only --exclude '.DS_Store' --exclude 'iTunes' /Users/kaushikgopal/Music/ /Volumes/Storage/Music/
```
- a – Archive includes a bunch of parameters to recurse directories, copy symlinks as symlinks, preserve permissions, preserve modification times, preserve group, preserve owner, and preserve device files. You usually want that option for all your backups.
- -v : Verbose
- -z : compress and send
- -n : Dry run
- -u : Update by checking filestamp
- -E : Make sure all the correct Metadata goes through
- -P or –progress : allows rsync to continue interrupted transfers and show a progress status for each file.
- –delete : delete files that don’t exist on the sending side
- –delete-excluded : also delete excluded files from dest dirs
- –exclude-from ‘/home/backup/exclude.txt’
Note: – A trailing / on a source name means “copy the contents of this directory”. Without a trailing slash it means “copy the directory”. This difference becomes particularly important when using the –delete option. – a trailing slash on the source changes this behavior to transfer all files from the directory src/bar on the machine foo into the /data/tmp/.

System Information

show current date and time
```
    date
```
show this month’s calendar
```
    cal
```
show system’s uptime
```
    uptime
```
Show user currently logged in
```
    whoami
```
show cpu information
```
    cat /proc/cpuinfo
```
show memory information
```
    cat /proc/meminfo 
```
directory free space
```
df -h
```
- h – in human readable form
Show disk usage or check file sizes or directory space usage
```
du -sh *
```
- s – summary
- h – in human readable form

File Permissions

        chmod  <octal permissions> <filename>

4 = read (r) ; 2 = write (w) ; 1 = execute (x)
order : owner/group/world
e.g1 chmod 777 – rwx for everyone
e.g2 chmod 755 – rw for owner and rx for everyone

Network Commands

ping the host
```
    ping <host>
```
get DNS for domain
```
    dig <domainname>
```
get whois for domain
```
    whois <domainname>
```
download file directly
```
    wget <file>
```
continue stopped download
```
    wget -c <file>
```
recursively download files from url
```
    wget -r <file>
```

SSH connection

connect to host as user
```
ssh user@host
```
connect to host as user using port p
```
ssh -p <port> user@host
```
connect to host and use bind port
```
ssh -D <port> user@host
```
connect to host and use bind port
```
ssh -D <port> user@host
```

Miscellaneous Cool Commands

Make two commands run one after the other with an & (take the example of killing a process and then reopening)
```
kill PID && open /System/Library/CoreServices/Finder.app
```
Check bitrate of mp files
```
afinfo filename |grep "bit rate"
```
add a hidden file to ensure finder doesn’t add index files
```
sudo touch /Volumes/drive_name/.metadata_never_index
```
find out what process or application is using a specified file at that given moment.
```
lsof /path/to/filename
```
find out what process or application is using a specified file in real time.
```
sudo opensnoop -f /var/log/system.log
```
find out what files are being used by an applicaiton.
```
sudo opensnoop -n Safari
```

Some useful links:

†

October 18th, 2010

Kaushik Gopal's Online Journal