Skip to content

Latest commit

 

History

History
347 lines (242 loc) · 6.01 KB

command_line.md

File metadata and controls

347 lines (242 loc) · 6.01 KB
Title
Command line stuff

List (ls)

ls [options] [paths]

Format

Switch Description
-1 One entry per line
-l Long view
-o Long view (without groups)
-C Multicolumn (sorted horizontally)
-x Multicolumn (sorted vertically)
---
-F Add / after directories
-G Color
{:.shortcuts}

Options

| -R | Recurse | | -a | Include hidden (dotfiles) | | -d */ | Only directories | | -A | Include hidden (but not . and ..) | {:.shortcuts}

Sorting

Switch Description
-r reverse order
-S sort by size
-t sort by time modified
-u sort by time accessed
-U sort by time created
-c sort by time status was changed
---
-h Human-readable size (3k)
{:.shortcuts}

Ls Samples

  ls -Cd */     # Only directories in column mode
  ls -dl */     # Only directories in long view mode
  ls -1d .*     # List only files with .dot(hiddden) 
  ls -llt -tr   # Sort order by date(most recent)
  ls -lah -S -r # List order by size

Tail

tail [-F | -f | -r] [-bN | -cN | -nN] [file ...]

Modes

| -f | follow | | -F | follow by filename (accounts for log rotation) | | -r | Reverse order | {:.shortcuts}

Options

| -bN | N*512 bytes | | -cN | N bytes | | -nN | N lines | | +N | Start from line N | {:.shortcuts}


View current disk space

$ df -h

Delete Files older than X Days

find . -type f -name '*.xz' -mtime +30 -exec ls {}

Find files are taking up the space

Linux
sudo apt install ncdu 
ncdu
Mac
brew install ncdu
ncdu

Copy/Sync Files and Directory to or From a Server

[root@tecmint]$ rsync -avz rpmpkgs/ root@192.168.0.101:/home/

root@192.168.0.101's password:

sending incremental file list
./
httpd-2.2.3-82.el5.centos.i386.rpm
...

Copy/Sync a Remote Directory to a Local Machine

[root@tecmint]# rsync -avzh root@192.168.0.100:/home/tarunika/rpmpkgs /tmp/myrpms

root@192.168.0.100's password:

receiving incremental file list

created directory /tmp/myrpms
rpmpkgs/
rpmpkgs/httpd-2.2.3-82.el5.centos.i386.rpm

...

Copy a File from a Remote Server to a Local Server with SSH

[root@tecmint]# rsync -avzhe ssh root@192.168.0.100:/root/install.log /tmp/

root@192.168.0.100's password:

receiving incremental file list
install.log
sent 30 bytes  received 8.12K bytes  1.48K bytes/sec
...

Show Progress While Transferring Data with rsync

[root@tecmint]# rsync -avzhe ssh --progress /home/rpmpkgs root@192.168.0.100:/root/rpmpkgs

root@192.168.0.100's password:

sending incremental file list

created directory /root/rpmpkgs
rpmpkgs/
rpmpkgs/httpd-2.2.3-82.el5.centos.i386.rpm

           1.02M 100%        2.72MB/s        0:00:00 (xfer#1, to-check=3/5)

Sudo

sudo [options] <command>

Listing

| -l | List allowed commands | {:.shortcuts}

Options

| -A | Use $SUDO_ASKPASS | | -b | Run in background | | -E | Preserve environment | | -H | use target's $HOME | | -n | Don't prompt for password | | -P | Preserve group vector | | -S | Read password from stdin | {:.shortcuts}

File descriptors

| -C fd | Close all open file descriptors | {:.shortcuts}

Prompt

| -p prompt | Custom prompt (-p "%p password:") | {:.shortcuts}

Interactive

Switch Description
-i [cmd] Interactive shell without variables
-s [cmd] Interactive shell
----
-u user run as this user
-g group run as this group
{:.shortcuts}

Timestamp

| -v | revalidate timestamp for 5 mins | | -k | invalidate timestamp | | -K | just like -k | {:.shortcuts}


wc (Word count)

... | wc [options]

| -c | Bytes | | -l | Lines | | -m | Characters (incl multi-byte) | | -w | Words | {:.shortcuts}


Search-and-replace in all files

    # All folders
    perl -p -i -e 's/hello/HELLO/g' **/*
    
    # Specific file
    perl -p -i -e 's/sending/receiving/g' tmux-client-57567.log

Grep

grep [options] [pattern] [file ...]

# find by filename 
$ grep -rl "rahul" /home/

# Search text in a file
grep "FATAL" /var/log/syslog

# Search multiple strings 
grep "FATAL|Warning|Error" /var/log/syslog

# Search in all files
grep "Error" /var/log/*            

# Search in specific extension files
grep "rahul" /var/log/*.log

Options

Switch Description
-A num Print num lines of training context
----
-G --basic-regexp (default)
-E --extended-regexp
-P --perl-regexp
----
-f file --file (Get patterns for file)
-F --fixed-strings
----
-h --no-filename
-H --with-filename
----
-l --files-with-matches (just print filenames)
-L --files-without-match
----
-r, -R --recursive
-v --invert-match
-i --ignore-case
{:.shortcuts}

Synonyms

egrep  =>  grep -E
fgrep  =>  grep -F

Ag the Silver search

More Samples

# Search string DHH with 3 rows extra informations
ag -C 3 DHH  

# Search string in specify path
ag DHH guides/ 

# Search string in filesnames that contain the word action.
ag readme -l -G action

# Search string only to match filenames that end with ec.
ag readme -l -i -G ec$

# Search string with --ignore-dir Flag
ag readme -l --ignore-dir=railties/lib

# Search string in specific extension files(.rb)
ag create_table -C 3 -G .rb$

# Search string map in ruby files with line and column numbers
ag --ruby map --column

# List all file-types
ag --list-file-types

Restart Linux Server using command prompt

   $  reboot
   $  poweroff
   $  shutdown -r 10  # Reboot server just after 10 minutes without displaying any message.
   $  shudwown -r now # Reboot server immediately without any message.
      # Reboot server at 02:10 AM with displaying proper message to user.
   $  shutdown -r 02:10 "System is going to reboot..."