Consulta comandos Linux comunes y ejemplos de terminal. Ten una referencia rápida mientras trabajas con servidores, contenedores, terminales y desarrollo.
It's a lot of orders from Linux.Tip: Press Ctrl+F to find Linux commands. Click a heading to collapse or expand it.
| Command code | Annotations |
|---|---|
| arch | Show machine processor structure (1) |
| uname -m | Display machine processor structure (2) |
| uname -r | Show kernel versions in use |
| dmidecode -q | Display hardware system widgets - (SMBIOS / DMI) |
| hdparm -i /dev/hda | List the structure characteristics of a disk |
| hdparm -tT /dev/sda | Perform test reading on disk |
| cat /proc/cpuinfo | Show CPUinfo information |
| cat /proc/interrupts | Show break |
| cat /proc/meminfo | Verify memory usage |
| cat /proc/swaps | Show which swap is used |
| cat /proc/version | Show kernel versions |
| cat /proc/net/dev | Display web adapter and statistics |
| cat /proc/mounts | Show loaded filesystems |
| lspci -tv | Row PCI Device |
| lsusb -tv | Show USB Devices |
| date | Show System Date |
| cal 2007 | Show calendar for 2007 |
| date 041217002007.00 | Set Date and Time - Months and Years. Seconds |
| clock -w | Save Time Changes to BIOS |
| Command code | Annotations |
|---|---|
| shutdown -h now | Shut down the system. |
| init 0 | Shut down the system. |
| telinit 0 | Shut down the system. |
| shutdown -h hours:minutes & | Shut down the system on schedule. |
| shutdown -c | Cancel closing the system as scheduled |
| shutdown -r now | Restart |
| reboot | Restart |
| logout | Write-offs |
| Command code | Annotations |
|---|---|
| cd /home | Enter '/ home' directory |
| cd .. | Back to the top level directory |
| cd ../.. | Returns the previous two-tier directory |
| cd | Enter your home directory |
| cd ~user1 | Enter your home directory |
| cd - | Returns last-held directory |
| pwd | Show work path |
| ls | View Files in Directory |
| ls -F | View Files in Directory |
| ls -l | Show details of files and directories |
| ls -a | Show hidden files |
| ls *[0-9]* | Show filenames and directories containing numbers |
| tree | Show tree structure of files and directories starting with root directories |
| lstree | Show tree structure of files and directories starting with root directories |
| mkdir dir1 | Create a directory called 'dir1' |
| mkdir dir1 dir2 | Create two directories simultaneously |
| mkdir -p /tmp/dir1/dir2 | Create a directory tree |
| rm -f file1 | Remove a file called 'file1 ' |
| rmdir dir1 | Remove a directory called 'dir1' |
| rm -rf dir1 | Remove a directory called 'dir1 'and delete its contents |
| rm -rf dir1 dir2 | Delete both directories and their contents. |
| mv dir1 new_dir | Rename/ Move a Directory |
| cp file1 file2 | Copy a file |
| cp dir/* . | Copy all files in a directory to the current working directory |
| cp -a /tmp/dir1 . | Copy a directory to the current working directory |
| cp -a dir1 dir2 | Copy a directory |
| ln -s file1 lnk1 | Create a soft link to a file or directory |
| ln file1 lnk1 | Create a physical link to a file or directory |
| touch -t 0712250000 file1 | Timetamp to modify a file or directory - (YYMMMDDhmm) |
| iconv -l | Lists known codes |
| iconv -f fromEncoding -t toEncoding inputFile > outputFile | Change character encoding |
| find . -maxdepth 1 -name *.jpg -print -exec convert | Batch resizing files in the current directory and sending them to the thumbnail directory (required for conversion from ImageMagick) |
| Command code | Annotations |
|---|---|
| find / -name file1 | Start searching files and directories from '/ ' |
| find / -user user1 | Search for files and directories belonging to the user 'user1 ' |
| find /home/user1 -name \*.bin | Search files with '.bin' endings in directory '/ home/user1' |
| find /usr/bin -type f -atime +100 | Search for executive documents that have not been used in the past 100 days |
| find /usr/bin -type f -mtime -10 | Search for files created or modified within 10 days |
| find / -name \*.rpm -exec chmod 755 '{}' \; | Search for files at '.rpm 'and define their privileges |
| find / -xdev -name \*.rpm | Search files ending with '.rpm ', ignoring removable devices such as optics, shortcuts, etc. |
| locate \*.ps | Search for files ending with '.ps' - start with the 'updaedb 'command |
| whereis halt | Show the location of a binary file, source code or man |
| which halt | Show a full path to a binary or an executable |
| Command code | Annotations |
|---|---|
| mount /dev/hda2 /mnt/hda2 | Mount a disk called hda2 - Determine directory '/ mnt/hda2' already exists |
| umount /dev/hda2 | Unmount a disk called hda2 - exit first from mount point '/ mnt/hda2' |
| fuser -km /mnt/hda2 | Force unloading when equipment is busy |
| umount -n /mnt/hda2 | Run unmounting without writing /etc/mtab files - very useful when the file is read-only or when the disk is full |
| mount /dev/fd0 /mnt/floppy | Mount a floppy |
| mount /dev/cdrom /mnt/cdrom | Mount a cdrom or dvdrom |
| mount /dev/hdc /mnt/cdrecorder | Mount a cdrew or dvdrom |
| mount /dev/hdb /mnt/cdrecorder | Mount a cdrew or dvdrom |
| mount -o loop file.iso /mnt/cdrom | Mount a file or ISO mirror file |
| mount -t vfat /dev/hda5 /mnt/hda5 | Mount a Windows FAT32 filesystem |
| mount /dev/sda1 /mnt/usbdisk | Mount a usb shortcut or flash drive |
| mount -t smbfs -o username=user,password=pass //WinClient/share /mnt/share | Mount a windows network share |
| Command code | Annotations |
|---|---|
| df -h | Show list of mounted partitions |
| ls -lSr |more | Sort files and directories by size |
| du -sh dir1 | Estimation directory 'dir1 'used disk space' |
| du -sk * | sort -rn | Show the size of files and directories in order of size |
| rpm -q -a --qf '%10{SIZE}t%{NAME}n' | sort -k1,1n | Space to show installed rpm packages in size by size (fedora, redhat class system) |
| dpkg-query -W -f='${Installed-Size;10}t${Package}n' | sort -k1,1n | Space to show installed Deb packages by size (ubuntu, debian class system) |
| Command code | Annotations |
|---|---|
| groupadd group_name | Create a new user group |
| groupdel group_name | Remove a user group |
| groupmod -n new_group_name old_group_name | Rename a user group |
| useradd -c "Name Surname " -g admin -d /home/user1 -s /bin/bash user1 | Create a user belonging to the "admin" user group |
| useradd user1 | Create a new user |
| userdel -r user1 | Remove a user ( '-r' excludes home directory) |
| usermod -c "User FTP" -g system -d /ftp/user1 -s /bin/nologin user1 | Modify User Properties |
| passwd | Modify password |
| passwd user1 | Modify a user password (root only) |
| chage -E 2020-12-31 user1 | Set the expiry date for the user password |
| pwck | Check the file format and syntax correction of '/etc/passwd 'and existing users |
| grpck | Check '/etc/passwd 'for file formats and syntax amendments and existing clusters |
| newgrp group_name | Login to a new group to change the default group of the newly created document |
| Command code | Annotations |
|---|---|
| ls -lh | Show permissions |
| ls /tmp | pr -T5 -W$COLUMNS | Split terminals into 5 columns |
| chmod ugo+rwx directory1 | Sets the permission of the owner (u), group (g) and others (o) to read (r), write (w) and execute (x) of the directory |
| chmod go-rwx directory1 | Delete reading and writing permissions for group (g) and others (o) on directories |
| chown user1 file1 | Change owner attribute of a file |
| chown -R user1 directory1 | Change owner properties of a directory while changing properties of all files in a directory |
| chgrp group1 file1 | Change group of files |
| chown user1:group1 file1 | Change owner and group attributes of a file |
| find / -perm -u+s | List all files in a system that are controlled by SUID |
| chmod u+s /bin/file1 | Set a binary file SUDID bit - users running the file are given the same privileges as owners |
| chmod u-s /bin/file1 | Disable a binary file SUID bit |
| chmod g+s /home/public | Set a directory of SID bits - similar to SUID, although this is for directories |
| chmod g-s /home/public | Disable a directory of SID bits |
| chmod o+t /home/public | Set a file STIKY bit - only valid owners are allowed to delete files |
| chmod o-t /home/public | Disable a directory of STIKY bits |
| Command code | Annotations |
|---|---|
| chattr +a file1 | Only additional documents are allowed to be read and written |
| chattr +c file1 | Allow this file to be automatically compressed/repressed by the kernel |
| chattr +d file1 | Dump will ignore this file while backuping the file system |
| chattr +i file1 | Set to unchangeable file, not to be deleted, modified, renamed or linked |
| chattr +s file1 | Allows a file to be safely deleted |
| chattr +S file1 | Once the application has performed a writing operation on this file, the system will immediately write the change to disk |
| chattr +u file1 | If the file is deleted, the system will allow you to restore this deleted file later. |
| lsattr | Show Special Properties |
| Command code | Annotations |
|---|---|
| bunzip2 file1.bz2 | Decompress a file called 'file1.bz2' |
| bzip2 file1 | Compress a file called `file1 ' |
| gunzip file1.gz | Unpression of a file called 'file1.gz' |
| gzip file1 | Compress a file called 'file1' |
| gzip -9 file1 | Maximum compression |
| rar a file1.rar test_file | Create a package called 'file1.r' |
| rar a file1.rar file1 file2 dir1 | Compress both 'file1', 'file2' and 'dir1' |
| rar x file1.rar | Unpressur rar bag |
| unrar x file1.rar | Unpressur rar bag |
| tar -cvf archive.tar file1 | Create a non-compressed tarball |
| tar -cvf archive.tar file1 file2 dir1 | Create an archive containing 'file1', 'file2' and 'dir1' |
| tar -tf archive.tar | Show contents in a package |
| tar -xvf archive.tar | Release a bag. |
| tar -xvf archive.tar -C /tmp | Release compression package to /tmp directory |
| tar -cvfj archive.tar.bz2 dir1 | Create a compression package in bzip2 format |
| tar -jxvf archive.tar.bz2 | Extract a compression package in bzip2 format |
| tar -cvfz archive.tar.gz dir1 | Create a compression package in gzip format |
| tar -zxvf archive.tar.gz | Extract a compression package in gzip format |
| zip file1.zip file1 | Create a compression package in zip format |
| zip -r file1.zip file1 file2 dir1 | Compress several files and directories into a zip package at the same time |
| unzip file1.zip | Unpress a zip compression package |
| Command code | Annotations |
|---|---|
| rpm -ivh package.rpm | Install a rpm package |
| rpm -ivh --nodeeps package.rpm | Install a rpm package without a dependency warning |
| rpm -U package.rpm | Update a rpm package without changing its profile |
| rpm -F package.rpm | Update a positive rpm package installed |
| rpm -e package_name.rpm | Remove a rpm package |
| rpm -qa | Show all installed rpm packages in the system |
| rpm -qa | grep httpd | Show rpm packages containing "httpd" in all names |
| rpm -qi package_name | Fetch special information about an installed package |
| rpm -qg "System Environment/Daemons" | Show a component's rpm package |
| rpm -ql package_name | Show a list of files provided by an installed rpm package |
| rpm -qc package_name | Show a list of profiles provided by an installed rpm package |
| rpm -q package_name --whatrequires | Show a list of dependencies with a rpm package |
| rpm -q package_name --whatprovides | Show the volume of a rpm package |
| rpm -q package_name --scripts | Show scripts executed during installation/removall |
| rpm -q package_name --changelog | Show a modified history of an rpm package |
| rpm -qf /etc/httpd/conf/httpd.conf | Confirm which rpm package provided the given document |
| rpm -qp package.rpm -l | Show list of files provided by an uninstalled rpm package |
| rpm --import /media/cdrom/RPM-GPG-KEY | Import Public Key Number Certificate |
| rpm --checksig package.rpm | Confirm the integrity of an rpm package |
| rpm -qa gpg-pubkey | Confirm the integrity of all rpm packages installed |
| rpm -V package_name | Check file size, license, type, owner, group, MD5 check and final change time |
| rpm -Va | Check all installed rpm packages in the system - Use carefully |
| rpm -Vp package.rpm | Confirm that a rpm package is not installed |
| rpm2cpio package.rpm | cpio --extract --make-directories *bin* | Run executable from an rpm package |
| rpm -ivh /usr/src/redhat/RPMS/`arch`/package.rpm | Install a constructed package from a rpm source code |
| rpmbuild --rebuild package_name.src.rpm | Construct a rpm package from a rpm source code |
| Command code | Annotations |
|---|---|
| yum install package_name | Download and install a rpm package |
| yum localinstall package_name.rpm | A rpm package will be installed to resolve all dependencies using your own software warehouse |
| yum update package_name.rpm | Update all installed rpm packages in the current system |
| yum update package_name | Update an rpm package |
| yum remove package_name | Remove a rpm package |
| yum list | List all packages installed on the current system |
| yum search package_name | Search for packages in the rpm repository |
| yum clean packages | Clean up rpm cache to delete downloaded packages |
| yum clean headers | Delete All Headers |
| yum clean all | Remove all cache packages and headers |
| Command code | Annotations |
|---|---|
| dpkg -i package.deb | Install/update a Deb package |
| dpkg -r package_name | Remove a Deb package from the system |
| dpkg -l | Show all installed Deb packages in the system |
| dpkg -l | grep httpd | Displays the Deb package containing "httpd" in all names |
| dpkg -s package_name | Get information about a special package installed in the system |
| dpkg -L package_name | Show a list of files provided by a deb package installed on the system |
| dpkg --contents package.deb | Show a list of files provided by a package that has not yet been installed |
| dpkg -S /bin/ping | Confirm which Deb package to deliver the given document |
| Command code | Annotations |
|---|---|
| apt-get install package_name | Install/update a Deb package |
| apt-cdrom install package_name | Install/update a Deb package from a CD |
| apt-get update | Upgrade packages in the list |
| apt-get upgrade | Upgrade all installed software |
| apt-get remove package_name | Remove a Deb package from the system |
| apt-get check | Confirm that the software repository is correct. |
| apt-get clean | Clear cache from downloaded packages |
| apt-cache search searched-package | Returns the package name containing the string to search for |
| Command code | Annotations |
|---|---|
| cat file1 | View the contents of the file from the first byte |
| tac file1 | View the contents of a file backwards from the last line |
| more file1 | View the contents of a long file |
| less file1 | Similar to the 'more ' command, but it allows the same reverse operation in the file as the positive operation |
| head -2 file1 | View the first two lines of a file |
| tail -2 file1 | View the last two lines of a file |
| tail -f /var/log/messages | View content added to a file in real time |
| Command code | Annotations |
|---|---|
| cat file1 | command( sed, grep, awk, grep, etc...) > result.txt | Merge the detailed text of a document and include the brief in a new document |
| cat file1 | command( sed, grep, awk, grep, etc...) >> result.txt | Merge the detailed text of a document and include the brief in an existing document |
| grep Aug /var/log/messages | Find the keyword "Aug" in file '/var/log/messages' |
| grep ^Aug /var/log/messages | Find words starting with "Aug" in document '/var/log/messages' |
| grep [0-9] /var/log/messages | Select all lines with numbers in '/var/log/messages' files |
| grep Aug -R /var/log/* | Search for string "Aug" in directory '/var/log' and subsequent directories |
| sed 's/stringa1/stringa2/g' example.txt | Replace "string1" with "string2" in example.txt |
| sed '/^$/d' example.txt | Remove all blank lines from example.txt files |
| sed '/ * #/d; /$/d 'example.txt from example.txt | Remove all comments and blank lines from the file |
| echo 'esempio' | tr '[:lower:]' '[:upper:]' | Merge cell contents up and down |
| sed -e '1d' result.txt | Exclude first row from fileexample.txt |
| sed -n '/stringa1/p' | View lines containing only "string1 " |
| sed -e 's/ *$//' example.txt | Delete last blank character for each row |
| sed -e 's/stringa1//g' example.txt | Remove only word "string1 " from the document and keep all remaining |
| sed -n '1,5p;5q' example.txt | View content from first to fifth rows |
| sed -n '5p;5q' example.txt | View Line 5 |
| sed -e 's/00*/0/g' example.txt | Replace more than one zero with one zero |
| cat -n file1 | Number of rows indicating files |
| cat example.txt | awk 'NR%2==1' | Delete all even lines in example.txt files |
| echo a b c | awk '{print $1}' | View first column of a row |
| echo a b c | awk '{print $1,$3}' | View first and third columns of one line |
| paste file1 file2 | Merge two files or two columns |
| paste -d '+' file1 file2 | Merge the contents of two files or two columns, distinguishing between "+" |
| sort file1 file2 | Sort the contents of two files |
| sort file1 file2 | uniq | Extract two files from a collection (one duplicate line is retained) |
| sort file1 file2 | uniq -u | Delete the intersection and leave other lines |
| sort file1 file2 | uniq -d | Extract from the intersection of two documents (only those documents present in both files) |
| comm -1 file1 file2 | Compare the contents of the two files to delete only those contained in `file1 ' |
| comm -2 file1 file2 | Compare the contents of both files to delete only what is contained in 'file2 ' |
| comm -3 file1 file2 | Compare the contents of the two documents to remove only those parts common to both documents |
| Command code | Annotations |
|---|---|
| dos2unix filedos.txt fileunix.txt | Convert a text file format from MMDOS to UNIX |
| unix2dos fileunix.txt filedos.txt | Convert a text file format from UNIX to MSDOS |
| recode ..HTML < page.txt > page.html | Convert a text file to html |
| recode -l | more | Show all allowed conversion formats |
| Command code | Annotations |
|---|---|
| badblocks -v /dev/hda1 | Check the bad disk on hda1 |
| fsck /dev/hda1 | Fix/check the integrity of the linux file system on the hda1 disk |
| fsck.ext2 /dev/hda1 | Fix/check the integrity of the ext2 file system on the hda1 disk |
| e2fsck /dev/hda1 | Fix/check the integrity of the ext2 file system on the hda1 disk |
| e2fsck -j /dev/hda1 | Fix/check the integrity of the ext3 file system on the hda1 disk |
| fsck.ext3 /dev/hda1 | Fix/check the integrity of the ext3 file system on the hda1 disk |
| fsck.vfat /dev/hda1 | Repair/check the integrity of the fat file system on the hda1 disk |
| fsck.msdos /dev/hda1 | Fix/check the integrity of the dos file system on hda1 disk |
| dosfsck /dev/hda1 | Fix/check the integrity of the dos file system on hda1 disk |
| Command code | Annotations |
|---|---|
| mkfs /dev/hda1 | Create a file system in subsector hda1 |
| mke2fs /dev/hda1 | Create a linux ext2 file system in subsector hda1 |
| mke2fs -j /dev/hda1 | Create a linux ext3 log type file system in subsector hda1 |
| mkfs -t vfat 32 -F /dev/hda1 | Create a FAT32 filesystem |
| fdformat -n /dev/fd0 | Formatting a Floppy |
| mkswap /dev/hda3 | Create a swap filesystem |
| Command code | Annotations |
|---|---|
| mkswap /dev/hda3 | Create a swap filesystem |
| swapon /dev/hda3 | Enable a new swap filesystem |
| swapon /dev/hda2 /dev/hdb3 | Enable two swap partitions |
| Command code | Annotations |
|---|---|
| dump -0aj -f /tmp/home0.bak /home | Make a complete backup of a '/home' directory |
| dump -1aj -f /tmp/home0.bak /home | Create interactive backup for a '/home' directory |
| restore -if /tmp/home0.bak | Restore an interactive backup |
| rsync -rogpav --delete /home /tmp | Synchronise directories on both sides |
| rsync -rogpav -e ssh --delete /home ip_address:/tmp | Through SSH channel rsync |
| rsync -az -e ssh --delete ip_addr:/home/public /home/local | Sync a remote directory to a local directory by ssh and compression |
| rsync -az -e ssh --delete /home/local ip_addr:/home/public | Sync local directories to remote directories by ssh and compression |
| dd bs=1M if=/dev/hda | gzip | ssh user@ip_addr 'dd of=hda.gz' | Perform a backup local disk operation on a remote host via ssh |
| dd if=/dev/sda of=/tmp/file1 | Backup disk content to a file |
| tar -Puf backup.tar /home/user | Perform an interactive backup to '/home/user' directory |
| ( cd /tmp/local/ && tar c . ) | ssh -C user@ip_addr 'cd /home/share/ && tar x -p' | Copy a directory contents in a remote directory via ssh |
| ( tar c /home ) | ssh -C user@ip_addr 'cd /home/backup-home && tar x -p' | Copy a local directory in a remote directory via ssh |
| tar cf - . | (cd /tmp/backup ; tar xf - ) | Locally copy one directory to another and keep the original permissions and links |
| find /home/user1 -name '*.txt' | xargs cp -av --target-directory=/home/backup/ --parents | Find and copy all files ending in '.txt' from one directory to another |
| find /var/log -name '*.log' | tar cv --files-from=- | bzip2 > log.tar.bz2 | Find all files ending with '.log 'and make a bzip package |
| dd if=/dev/hda of=/dev/fd0 bs=512 count=1 | Do an action to copy MBR (Master Boot Record) to diskette |
| dd if=/dev/fd0 of=/dev/hda bs=512 count=1 | Restore MBR content from saved to disk backup |
| Command code | Annotations |
|---|---|
| cdrecord -v gracetime=2 dev=/dev/cdrom -eject blank=fast -force | Empty a rewritten CD contents |
| mkisofs /dev/cdrom > cd.iso | Create a soo mirror file on disk |
| mkisofs /dev/cdrom | gzip > cd_iso.gz | Create a compressed CD-ROM image file on disk |
| mkisofs -J -allow-leading-dots -R -V "Label CD" -iso-level 4 -o ./cd.iso data_cd | Creates a soo mirror file for a directory |
| cdrecord -v dev=/dev/cdrom cd.iso | Burn an ISO mirror file |
| gzip -dc cd_iso.gz | cdrecord dev=/dev/cdrom - | Burn a compressed ISO mirror file |
| mount -o loop cd.iso /mnt/iso | Mount an ISO mirror file |
| cd-paranoia -B | Transfer audio track from a CD to a wav file |
| cd-paranoia -- "-3" | Transfer audio track from a CD to a wav file (parameter-3) |
| cdrecord --scanbus | Scan the bus to identify the scsi channel |
| dd if=/dev/hdc | md5sum | Verify md5sum encoding of a device, e. g. a CD |
| Command code | Annotations |
|---|---|
| dhclient eth0 | Enable `eth0' network device in dhcp |
| ethtool eth0 | Show traffic statistics for netcard "eth0" |
| host www.example.com | Find hostname to parse name and IP address and mirror |
| hostname | Show hostname |
| ifconfig eth0 | Show the configuration of an Ethernet |
| ifconfig eth0 192.168.1.1 netmask 255.255.255.0 | Control IP Address |
| ifconfig eth0 promisc | Set `eth0 ' in mixed mode to sniff data packages (sniffing) |
| ifdown eth0 | Disable an "eth0" network device |
| ifup eth0 | Enable an "eth0" network device |
| ip link show | Show the connectivity of all network devices |
| iwconfig eth1 | Display the configuration of a wireless card |
| iwlist scan | Show wireless network |
| mii-tool eth0 | Show `eth0 ' Connection Status |
| netstat -tup | Show all active network connections and their PIDs |
| netstat -tup1 | Show all network services listening to the system and their PID |
| netstat -rn | Display a router, similar to the "route-n" command |
| nslookup www.example.com | Find hostname to parse name and IP address and mirror |
| route -n | Show Route Table |
| route add -net 0/0 gw IP Gateway | Control preset gateway |
| route add -net 192.168.0.0 netmask 255.255.0.0 gw 192.168.1.1 | Control the static route to the network `192.168.0.0/16' |
| route del 0/0 gw IP gateway | Remove static route |
| echo “1”> /proc/sys/net/ipv4/ip_foward | Activate IP Forward |
| tcpdump tcp port 80 | Show all HTTP loops |
| whois www.example.com | Find in Whois Database |
| Command code | Annotations |
|---|---|
| mount -t smbfs -o username=user,password=pass //WinClient/share/mnt/share | Mount a windows network share |
| nbtscan ip addr | Name of netbios |
| nmblookup -A ip addr | Name of netbios |
| smbclient -L ip addr/hostname | Show remote sharing of a windows host |
| smbget -Rr smb://ip addr/share | You can download files from a windows mainframe through smb like wget. |
| Command code | Annotations |
|---|---|
| iptables -t filter -L | Show all links to the filter table |
| iptables -t nae -L | Show all links to the nat watch |
| iptables -t filter -F | Clear all rules based on filter tables |
| iptables -t nat -F | Clean up all the rules based on the nat table. |
| iptables -t filter -X | Remove all links created by users |
| iptables -t filter -A INPUT -p tcp --dport telnet -j ACCEPT | Allow telnet access |
| iptables -t filter -A OUTPUT -p tcp --dport telnet -j DROP | Stop telnet access. |
| iptables -t filter -A FORWARD -p tcp --dport pop3 -j ACCEPT | Allow POP3 connections on forward chain |
| iptables -t filter -A INPUT -j LOG --log-prefix | Record all sealed packages in the links. |
| iptables -t nat -A POSTROUTING -o eth0 -j MASQUERADE | Set a PAT (port address conversion) to cover up dispatch packages at eth0 |
| iptables -t nat -A POSTROUTING -d 192.168.0.1 -p tcp -m tcp --dport 22-j DNAT --to-destination 10.0.0.2:22 | Move package sent to one host address to another host |
| Command code | Annotations |
|---|---|
| free -m | List RAM status in megagrams |
| kill -9 process id | Forced closure of the process and ending it |
| kill -1 process id | Force a process to reload its configuration |
| last reboot | Show restart history |
| lsmod | kernel module for list status |
| lsof -p process id | List of files opened by a process |
| lsof /home/user1 | List of files opened in the system path |
| ps -eafw | Rollinux Task |
| ps -e -o pid,args --forest | List Linux tasks in a hierarchical manner |
| pstress | Show program as tree map |
| smartctl -A /dev/hda | Monitor the reliability of hard drive devices by using SMART |
| smartctl -i /dev/hda | Check if SMART of a hard drive device is enabled |
| strace -c ls >/dev/null | Lists made and received in one process |
| strace -f -e open ls >/dev/null | Rollout Call |
| tail /var/log/dmesg | Show internal events during kernel guidance |
| tail /val/log/messages | Show System Events |
| top | List the Linux missions using the largest CPU resources |
| watch -nl ‘cat /proc/interrupts’ | Rolling out real time. |
| Command code | Annotations |
|---|---|
| alias hh='history' | Set an alias for commandhistory |
| apropos ...keyword | A list of commands that include program keywords that are particularly useful when you only know what program is doing and don't remember the command. |
| chsh | Change shell command |
| chsh --list-shells | A good order to know if you have to connect remotely to another machine. |
| gpg -c filel | Encrypt a file with GNU Privacy Guard |
| gpg filel.gpg | Decrypt a file with GNU Privacy Guard |