apropos- display a list of all topics in the man pages by command names based on keyword search usage: apropos keyword<\/p>\n
bg\/fg – background or foreground a job (command) – adding an ampersand ( & ) to the command runs the job in the background<\/p>\n fg – Continues a stopped job by running it in the foreground ————– OPTIONS:<\/p>\n -b\tPrint the byte offset of input file before each line of output. Regular expressions can also be used.<\/p>\n fgrep – a faster version of grep which does not support regular expressions, fgrep is equal to grep -F<\/p>\n rgrep – a recursive version of grep. rgrep can recursively descend through directories as it greps for the specified pattern. rgrep is similar to grep -r.<\/p>\n more info here: ————–<\/p>\n fc – views, edits, and executes commands from the history list. This is a shell builtin.<\/p>\n Options: ————–<\/p>\n od\/hexdump\/xxd – basically does hexdumps with different features – make a hexdump or do the reverse —————<\/p>\n ldd – List dependencies or the shared libraries used by a program, ~$ cd \/usr\/bin ——————-<\/p>\n logsave – this command saves the output of a command to a log file:<\/p>\n Doesn’t sound overly interesting, does it? Well the magic of logsave is that if the file, in our case \/var\/log\/partsize, does not exist then logsave will queue the data in memory and wait for the file to appear. This is perfect for tracking the output of commands run doing the boot process when the partition you are writing to is not yet mounted.<\/p>\n —————-<\/p>\n lsof – list files currently in use lsof -a -u david -i @10.1.13.11 everything running as david connected to 10.1.13.11 mkfifo – used to create a FIFO (first in, first out) or (named pipe) to permit communications between 2 unrelated processes. When created, this will be a file system persistent object (regular flat file). —————-<\/p>\n nohup – runs a command that keeps running after logout. The command is in principle immune to hangups, and must have output to a non tty.<\/p>\n —————-<\/p>\n pstree – shows running processes as a tree. —————-<\/p>\n script – Records everything printed on your screen —————–<\/p>\n strace – traces the system calls of a program while the program is running strace will not provide stack traces, gdb (backtrace) is the program to use<\/p>\n —————–<\/p>\n strings – returns each string of printable characters in a binary file<\/p>\n strings -f tells strings to begin each line of its output with the name of the file from which it is returning a particular string, followed by a colon and then by several spaces<\/p>\n —————–<\/p>\n tee – copy standard input to standard output and one or more files<\/p>\n xload – displays a graphic of the system load if X is enabled<\/p>\n —————–<\/p>\n Another useful control operator is the \u2018&\u2019 (ampersand) —————–<\/p>\n —————–<\/p>\n —————–<\/p>\n [Ctrl]c – kill the current process apropos- display a list of all topics in the man pages by command names based on keyword search usage: apropos keyword apropos pstree apropos editor ————- bg\/fg – background or foreground a job (command) – adding an ampersand ( & ) to the command runs the job in the background bg [options] [job] 1) start… <\/p>\napropos pstree<\/code>
\napropos editor<\/code>
\n————-<\/p>\nbg [options] [job]<\/code>
\n1) start application
\n2) ctrl +z – stop the current job
\n3) bg – moves the command to background and continue running
\n4) jobs – display the jobs in the shell<\/p>\n
\nfg ‘specify job #’ – %job Specifies the job that you want to run in the foreground.
\nfg 1 – will run job 1 process in the foreground<\/p>\n
\negrep – search files for lines that match regular expressions. Runs faster than grep and fgrep
\negrep [options] pattern [file]<\/code><\/p>\n
\n-c\tPrint’s the count of line matched.
\n-e pattern list\tSearches the pattern list.
\n-f file\tTake the list of full regular expressions from file.
\n-h\tPrint matched lines but not filenames.
\n-i\tIgnore changes in case; consider upper- and lower-case letters equivalent.
\n-n\tPrint line and line number.
\n-q\tPrints in quite mode, prints nothing.
\n-r\tRecursively read all files in directories and in subdirectories found.
\n-v\tPrints all the lines that do not match.
\n-V\tPrint Version.
\n-w\tMatch on whole word only.
\nstrings\tSpecify a pattern to be used during the search for input.
\nfile\tA path name of a file to be searched for the patterns. If no file operands are specified, the standard input will be used.<\/p>\negrep \"list|quote|print\" file.txt<\/code> – Would search for patterns of list quote and print in the file file.txt.<\/p>\n
\nhttp:\/\/www.linuxconfig.org\/Grep_egrep_fgrep_rgrep<\/a>
\nhttp:\/\/www.cyberciti.biz\/faq\/howto-use-grep-command-in-linux-unix\/<\/a><\/p>\nfc [-e ename] [-nlr] [first] [last]<\/code> – a range of commands from first to last is selected from the history list<\/p>\nfc -s [pat=rep] [cmd]<\/code> – command is re-executed after each instance of ‘pat’ is replaced by ‘rep’<\/p>\n
\n-e ENAME select which editor to use. Default is FCEDIT, then EDITOR, then vi
\n-l list lines instead of editing
\n-n omit line numbers when listing
\n-r reverse the order of the lines (newest listed first<\/p>\n
\nxxd -h[elp]
\nxxd [options] [infile [outfile]]
\nxxd -r[evert] [options] [infile [outfile]]
\nxxd -r no parse errors<\/p>\n
\nmust use full path or be in dir if command is not in path
\n
\nldd `which freshclam`
\nldd -v \/usr\/bin\/nano<\/p>\n
\n\/usr\/bin$ ldd -v nano<\/code><\/p>\n$ logsave \/var\/log\/partsize df \u2013h<\/code>
\nHere, the logsave command saves the output of the df command to the file \/var\/log\/partsize file \u2013 it will also add a timestamp and output the results of the command to standard out.<\/p>\n
\n
\nlsof -p -processid - see all files in use by a particular process
\nlsof -i -Show all connections
\nlsof -iTCP Show only TCP connections
\nlsof -i :22 shows all networking related to a given port
\nlsof -i@192.168.1.8 show connections to a specific host, use @host
\nlsof -i@192.168.1.8:22 Show connections based on the host and the port using @host:port
\nlsof -i| grep LISTEN shows what ports your system is waiting for connections on
\nlsof -i| grep ESTABLISHED shows current active connections
\nlsof -u david Show what a given user has open
\nlsof -c syslog-ng what files and network connections a command is using
\nlsof \/var\/log\/messages what's interacting with that file
\nlsof -p 10291 what a given process ID has open
\nlsof -i4 -nP show if any process is holding open tcp 80<\/p>\n
\nkill -9 `lsof -t -u david kill everything a user has open
\nlsof +L1 shows all open files that have a link count less than 1
\n<\/code>
\n—————-<\/p>\n
\nmkfifo pipe create a named pipe with the name pipe<\/p>\nnohup command-name &
\nnohup myscript.sh &<\/code>
\nctrl +D or exit – script continues to run<\/p>\n
\npstree [options] [pid or username]
\n-p shows a PID in parenthesis after each process name
\n-n sorts output order by PIDs instead of default alphabetic order
\n-h highlights the current process and all of its ancestors
\n-l prevents the truncation of long lines
\n-u tells pstree to show the owner of a process
\n-a shows the command line arguments for each process that was initiated by a user<\/p>\npstree joe
\npstree root<\/code><\/p>\n
\nscript [-a] filename<\/code>
\n-a append the session record to filename, rather than overwrite it.
\nfilename – the name of the file that the results will be stored in.
\nscript ends when the forked shell exits (user types exit) or when CTRL-D is typed<\/p>\n
\nstrace -o strace_ls_output.txt ls <\/code>(logs the info to a file)
\n-f option causes strace to trace child process created by the fork(2) system call
\n-ff splits the traces into separate files according to process
\n-p option allows one to attach to an already existing process by its pid number
\n-s with a specified (integer) length adjusts the maximum length of strings to print.<\/p>\nstrings [options] file_name(s)<\/code> displays all strings that are at least four characters in length in the file<\/p>\nstrings -n 2 file1 file2<\/code> return strings which are at least the number of that integer in length<\/p>\nls *.txt | wc -l | tee \/dev\/tty count.txt<\/code>
\nthe ls command would list all .txt files in the current directory, take a word count (wc) by the amount of lines (-l) and the output displayed to the \/dev\/tty (terminal) will be sent to the count.txt.
\n—————–<\/p>\n
\nEnding a command with \u2018&\u2019 runs the command with a new PID (subshell), releasing the command line back to you. Useful for running a background process.<\/p>\n[Tab][Tab]
\nroot@host# Display all 3119 possibilities? (y or n) <\/code>
\n– prints a list of all available commands. This is just an example of autocomplete with no restriction on the first letter.<\/p>\nx[Tab][Tab]<\/code> – prints a list of all available completions for a command, where the beginning is “x”<\/p>\n
\n[Ctrl]d – logout from the current terminal
\n[Ctrl]s – stop transfer to current terminal
\n[Ctrl]q – resume transfer to current terminal. This should be tried if the terminal stops responding.
\n[Ctrl]z – send current process to the background<\/p>\n","protected":false},"excerpt":{"rendered":"