collegeCurriculum

Bash Commands

Create the following directory structure

flowchart TD
 A[nirmala] --> B[ug]
 A --> C[pg]
 B --> D[ba]
 B --> E[bsc]
 B --> F[bcom]
 B --> G[bca]
 C --> H[ma]
 C --> I[msc]
 C --> J[mcom]
 C --> K[mca]

mkdir -p nirmala/{ug/{ba,bsc,bcom,bca},pg/{ma,msc,mcom,mca}} #you could also expand it

Remove the directory bcom
```
rmdir nirmala/ug/bcom
```
Change to parent directory
```
cd ..
```
Display the contents of current directory in detail
```
ls -al 
```
Display the current path
```
pwd 
```
Change the name of bca to nbca
```
mv nirmala/ug/bca nirmala/ug/nbca
```

Change to nbca
```
cd nirmala/ug/nbca
```

Create file bcastudent

cat > bcastudents #a blank cursor will appear, and type what you want to store, Ctrl+c to exit and save

Sort the names in bcastudents
```
sort bcastudents 
```
Create a file in mca directory and after that display the sorted content
```
cd ../../pg/mca 
cat > mcastudents
sort mcastudents
```

Append into bcastudents

cd ../../ug/nbca
cat >> bcastudents #append to the file
cat bcastudents #print the whole file

Search for a particular data in bcastudents
```
grep "keyword" bcastudents
```
Display all files including hidden
```
ls -a
```
Count the number of lines in bcastudents
```
wc -l bcastudents
```
Translate the lowercase letters into uppercase letters in bcastudents
```
cat bcastudents | tr "[a-z]" "[A-Z]"
```
Implement pr command
```
pr bcastudents
```

Create files f1, f2, f3, f4 in nbca

cat >> f1
cat >> f2
cat >> f3
cat >> f4

Implement find command
```
find -name f1 -print
```
Delete file f4
```
rm f4
```
Create a file f5 and implement cut command
```
cat >> f5
cut -c 1,2 f5
```

Implement head and tail

head -2 bcastudents
tail -2 bcastudents

Implement file command
```
file *
```
File comparison
```
cmp f1 f2
diff f1 f2
```
Implement chmod command
```
chmod 777 f5
```

Mathematical Commands

Workout various mathematical commands

bc #ctrl+d to exit
expr 2 + 5 #space is needed between operands and operator
factor 49

Miscellaneous Commands

Implement the working of ls command
```
cd ..
touch f1 f2
ls
ls f*
ls f?
ls b*
```
Implement various system related commands
```
uname
who
who am i
hostname
```
Get the shell details
```
echo $0
cat /etc/shells
echo $PATH
```
Get terminal name
```
tty
```
Get primary prompt
```
echo $PS1
```
Get secondary prompt
```
echo $PS2
```

Date Command

Implement cal command
```
cal
```
Display current time and date
```
date
```
Get current date
```
date "+%D"
```
Get current day
```
date "+%A"
```
Get current month
```
date "+%h"
```
Get last 2 digits of current year
```
date "+%y"
```
Get current year
```
date "+%Y"
```
Get current time
```
date "+%T"
```
Get current hour
```
date "+%H"
```
Get current minute
```
date "+%M"
```
Get current second
```
date "+%S"
```

df
du

PS Command

Get the details of processes
```
ps
```

TEE command

Redirect the output of a process into another file
```
ls -l | tee f1
```

Other Commands

Get the login name of the user
```
logname
```
Redirect error into a file
```
las -l 2> f5
cat f5
```

VI EDITOR

Create a file f1 and save content into it and quit
```
vi f1
:wq
```
Open the same file and copy the first line and paste it into third line
```
vi f1
:1co3
```
Delete the second and third line
```
:2,3d
```
Delete a word from current position
```
dw
```
Save and Exit from the file
```
:wq
```