From 2749a3154e6c930899926ea8114783391c138fe8 Mon Sep 17 00:00:00 2001 From: Adnan Ahmed Date: Sat, 1 Apr 2017 17:08:39 +0400 Subject: [PATCH] minor updates --- README.md | 46 +--------------------------------------------- 1 file changed, 1 insertion(+), 45 deletions(-) diff --git a/README.md b/README.md index 8f06620..12416a4 100644 --- a/README.md +++ b/README.md @@ -24,7 +24,6 @@ ### a. `export` Displays all environment variables and if you want to get detail of specific variable then use `echo $VARIABLE_NAME` -Syntax: ```bash export ``` @@ -43,7 +42,6 @@ $ echo $SHELL ### b. `whereis` Finds out where a specific binary is on your system. -Syntax: ```bash whereis name ``` @@ -55,7 +53,6 @@ $ whereis php ### c. `which` Locate a program file in the user's path. This command will prints full path of the executable(s). It does this by searching the directories listed in the environment variable PATH. -Syntax: ```bash which program_name ``` @@ -95,7 +92,6 @@ Clears content on window ### a. `ls` Lists your files. It has a lot of options like `-l` lists files in 'long format', which contains the exact size of the file, who owns the file and who has the right to look at it, and when it was last modified. `-a` lists all files, including hidden files. For more information on this command check this [link](https://ss64.com/bash/ls.html) -Syntax: ```bash ls option ``` @@ -114,7 +110,6 @@ drwxr-xr-x 17 adnan staff 578 Mar 27 23:36 .git ### b. `touch` Creates or updates your file -Syntax: ```bash touch filename ``` @@ -125,28 +120,24 @@ $ touch trick.md ### c. `cat` Places standard input into file. Means that it opens the file in terminal for you to edit -Syntax: ```bash cat > filename ``` ### d. `more` Shows the first part of a file (move with space and type q to quit) -Syntax: ```bash more filename ``` ### e. `head` Outputs the first 10 lines of file -Syntax: ```bash head filename ``` ### f. `tail` Outputs the last 10 lines of file. Use `-f` to output appended data as the file grows -Syntax: ```bash tail filename ``` @@ -154,7 +145,6 @@ tail filename ### g. `mv` Moves a file from one location to other -Syntax: ```bash mv filename1 filename2 ``` @@ -162,7 +152,6 @@ Where `filename1` is the source path to the file and `filename2` is the destinat ### h. `cp` Copies a file from one location to other -Syntax: ```bash cp filename1 filename2 ``` @@ -172,56 +161,48 @@ Where `filename1` is the source path to the file and `filename2` is the destinat Removes a file. But if you will apply this command on a directory directory, it will gives you an error `rm: directory: is a directory` So in order to remove directory you have to pass `-rf` to remove all the content of the directory recursively -Syntax: ```bash rm filename ``` ### j. `diff` Compares files, and shows where they differ -Syntax: ```bash diff filename1 filename2 ``` ### k. `chmod` Lets you change the read, write, and execute permissions on your files -Syntax: ```bash chmod -options filename ``` ### l. `gzip` Compresses files -Syntax: ```bash gzip filename ``` ### m. `gunzip` Un-compresses files compressed by gzip -Syntax: ```bash gunzip filename ``` ### n. `gzcat` Lets you look at gzipped file without actually having to gunzip it -Syntax: ```bash gzcat filename ``` ### o. `lpr` Print the file -Syntax: ```bash lpr filename ``` ### p. `lpq` Check out the printer queue -Syntax: ```bash lpq ``` @@ -235,7 +216,6 @@ active adnanad 59 demo 399360 bytes ### q. `lprm` Remove something from the printer queue -Syntax: ```bash lprm jobnumber ``` @@ -266,7 +246,6 @@ lprm jobnumber ### a. `awk` Awk is most usefull command for handling text files. It operates on entire file line by line. By default it uses whitespace to separate the fields. The most common syntax for awk command is -Syntax: ```bash awk '/search_pattern/ { action_to_take_if_pattern_matches; }' file_to_parse ``` @@ -295,7 +274,6 @@ For more detail on how to use `awk`, check following [link](https://www.cybercit ### b. `grep` Looks for text inside files. You can use grep to search for lines of text that match one or many regular expressions, and outputs only the matching lines. -Syntax: ```bash grep pattern filename ``` @@ -314,7 +292,6 @@ And `-w` to search for words only. For more detail on `grep`, check following [l ### c. `wc` Tells you how many lines, words and characters there are in a file -Syntax: ```bash wc filename ``` @@ -370,7 +347,6 @@ TODO ### a. `mkdir` Makes a new directory -Syntax: ```bash mkdir dirname ``` @@ -387,7 +363,6 @@ cd dirname ### c. `pwd` Tells you in which directory you currently are -Syntax: ```bash pwd ``` @@ -429,12 +404,10 @@ pwd ### a. `ssh` ssh (SSH client) is a program for logging into a remote machine and for executing commands on a remote machine. -Syntax: ```bash ssh user@host ``` This command also accepts an option `-p` that can to used to connect to specific port. -Syntax: ```bash ssh -p port user@host ``` @@ -446,8 +419,7 @@ Return current logged in username Allows the current logged user to change his password ### d. `quota` -Shows what your disk quota is -Syntax: +Shows what your disk quota is ```bash quota -v ``` @@ -466,21 +438,18 @@ Displays who is online ### i. `finger` Displays information about user -Syntax: ```bash finger username ``` ### j. `uname` Shows kernel information -Syntax: ```bash uname -a ``` ### k. `man` Shows the manual for specified command -Syntax: ```bash man command ``` @@ -490,35 +459,30 @@ Shows disk usage ### m. `du` Shows the disk usage of the files and directories in filename (du -s give only a total) -Syntax: ```bash du filename ``` ### n. `last` Lists your last logins of specified user -Syntax: ```bash last yourUsername ``` ### o. `ps` Lists your processes -Syntax: ```bash ps -u yourusername ``` ### p. `kill` Kills (ends) the processes with the ID you gave -Syntax: ```bash kill PID ``` ### q. `killall` Kill all processes with the name -Syntax: ```bash killall processname ``` @@ -534,28 +498,24 @@ Brings the most recent job in the foreground. ### u. `ping` Pings host and outputs results -Syntax: ```bash ping host ``` ### v. `whois` Gets whois information for domain -Syntax: ```bash whois domain ``` ### w. `dig` Gets DNS information for domain -Syntax: ```bash dig domain ``` ### x. `wget` Downloads file -Syntax: ```bash wget file ``` @@ -634,7 +594,6 @@ ${#varname} # returns the length of the value of the variable as a character ## 2.3. Functions As in almost any programming language, you can use functions to group pieces of code in a more logical way or practice the divine art of recursion. Declaring a function is just a matter of writing function my_func { my_code }. Calling a function is just like calling another program, you just write its name. -Syntax: ```bash functname() { shell commands @@ -661,7 +620,6 @@ When you will run above example the `hello` function will output "world!". The a The conditional statement in bash is similar to other programming languages. Conditions have many form like the most basic form is `if` expression `then` statement where statement is only executed if expression is true. -Syntax: ```bash if [expression]; then will execute only if expression is true @@ -672,7 +630,6 @@ fi Sometime if conditions becoming confusing so you can write the same condition using the `case statements`. -Syntax: ```bash case expression in pattern1 ) @@ -772,7 +729,6 @@ cd hotellogs # 4. Debugging You can easily debug the bash script by passing different options to `bash` command. For example `-n` will not run commands and check for syntax errors only. `-v` echo commands before running them. `-x` echo commands after command-line processing. -Syntax: ```bash bash -n scriptname bash -v scriptname