Frequently Asked Questions About Linux / UNIX » BASH Shell http://www.cyberciti.biz/faq Every answer asks a more beautiful question. Fri, 03 Feb 2012 22:38:32 +0000 en hourly 1 http://wordpress.org/?v=3.3.1 HowTo Run a Script In Linuxhttp://www.cyberciti.biz/faq/howto-run-a-script-in-linux/ http://www.cyberciti.biz/faq/howto-run-a-script-in-linux/#comments Thu, 10 Nov 2011 12:17:52 +0000 Vivek Gite http://www.cyberciti.biz/faq/?p=11198 How do I run a Linux shell script? How can I run a script in Linux?]]> http://www.cyberciti.biz/faq/howto-run-a-script-in-linux/feed/ 4 Linux / Unix curl: Pass HTTP Refererhttp://www.cyberciti.biz/faq/linux-unix-appleosx-bsd-curl-command-httpreferer/ http://www.cyberciti.biz/faq/linux-unix-appleosx-bsd-curl-command-httpreferer/#comments Sun, 06 Nov 2011 22:01:47 +0000 Vivek Gite http://www.cyberciti.biz/faq/?p=11185 How do I pass the referrer (HTTP referrer)as an HTTP header field using curl command under Linux OR Unix operating systems?]]> http://www.cyberciti.biz/faq/linux-unix-appleosx-bsd-curl-command-httpreferer/feed/ 0 Bash Shell: Find Out If a Variable Is Set or Nothttp://www.cyberciti.biz/faq/linux-unix-howto-check-if-bash-variable-defined-not/ http://www.cyberciti.biz/faq/linux-unix-howto-check-if-bash-variable-defined-not/#comments Sun, 25 Sep 2011 10:34:33 +0000 Vivek Gite http://www.cyberciti.biz/faq/?p=11132 How do I check if a bash shell variable called $input is defined or not under BSD / Apple OS X / Unix / Linux like operating systems?]]> http://www.cyberciti.biz/faq/linux-unix-howto-check-if-bash-variable-defined-not/feed/ 1 Linux / UNIX: HowTo Empty Directoryhttp://www.cyberciti.biz/faq/howto-empty-linux-unix-directory-delete-all-files/ http://www.cyberciti.biz/faq/howto-empty-linux-unix-directory-delete-all-files/#comments Tue, 20 Sep 2011 21:14:33 +0000 Vivek Gite http://www.cyberciti.biz/faq/?p=11109 How do I empty a directory (delete all files) under Linux / Unix without deleting directory itself?]]> http://www.cyberciti.biz/faq/howto-empty-linux-unix-directory-delete-all-files/feed/ 7 awk / cut: Skip First Two Fields and Print the Rest of Linehttp://www.cyberciti.biz/faq/unix-linux-bsd-appleosx-skip-fields-command/ http://www.cyberciti.biz/faq/unix-linux-bsd-appleosx-skip-fields-command/#comments Wed, 13 Jul 2011 07:51:13 +0000 Vivek Gite http://www.cyberciti.biz/faq/?p=10831 I'd like to skip first two or three fields at the the beginning of a line and print the rest of line. Consider the following input:
This is a test Giving back more than we take
I want my input file with the following output:
a test more than we take
How do I printing lines from the nth field using awk under UNIX or Linux operating systems?]]> http://www.cyberciti.biz/faq/unix-linux-bsd-appleosx-skip-fields-command/feed/ 1 Bash Shell Count Number of Characters In a String or Wordhttp://www.cyberciti.biz/faq/unix-linux-appleosx-bsd-bash-count-characters-variables/ http://www.cyberciti.biz/faq/unix-linux-appleosx-bsd-bash-count-characters-variables/#comments Wed, 22 Jun 2011 14:36:07 +0000 Vivek Gite http://www.cyberciti.biz/faq/?p=10750 How do I count and print particular character (say D or digit 7) in a string or variable under Bash UNIX / Linux shell? ]]> http://www.cyberciti.biz/faq/unix-linux-appleosx-bsd-bash-count-characters-variables/feed/ 6 Bash C Style For Loop Example and Syntaxhttp://www.cyberciti.biz/faq/linux-unix-applesox-bsd-bash-cstyle-for-loop/ http://www.cyberciti.biz/faq/linux-unix-applesox-bsd-bash-cstyle-for-loop/#comments Tue, 07 Jun 2011 23:34:37 +0000 Vivek Gite http://www.cyberciti.biz/faq/?p=10656 How do I use the bash C style for loop under UNIX or Linux operating systems?]]> http://www.cyberciti.biz/faq/linux-unix-applesox-bsd-bash-cstyle-for-loop/feed/ 1 Linux: What is Dash ( /bin/dash ) Shell?http://www.cyberciti.biz/faq/debian-ubuntu-linux-binbash-vs-bindash-vs-binshshell/ http://www.cyberciti.biz/faq/debian-ubuntu-linux-binbash-vs-bindash-vs-binshshell/#comments Sat, 28 May 2011 12:43:18 +0000 Vivek Gite http://www.cyberciti.biz/faq/?p=10598 What is /bin/dash? I noticed that the default system shell /bin/sh was changed to /bin/dash. Why was this change made?]]> http://www.cyberciti.biz/faq/debian-ubuntu-linux-binbash-vs-bindash-vs-binshshell/feed/ 3 Linux / UNIX: Run Command a Number of Times In a Rowhttp://www.cyberciti.biz/faq/bsd-appleosx-linux-bash-shell-run-command-n-times/ http://www.cyberciti.biz/faq/bsd-appleosx-linux-bash-shell-run-command-n-times/#comments Thu, 19 May 2011 21:20:31 +0000 Vivek Gite http://www.cyberciti.biz/faq/?p=10514 How do I run "foo" command 10 times (or n times) under Linux or UNIX like operating systems?]]> http://www.cyberciti.biz/faq/bsd-appleosx-linux-bash-shell-run-command-n-times/feed/ 6 Linux: TMOUT To Automatically Log Users Outhttp://www.cyberciti.biz/faq/linux-tmout-shell-autologout-variable/ http://www.cyberciti.biz/faq/linux-tmout-shell-autologout-variable/#comments Wed, 18 May 2011 07:57:20 +0000 Vivek Gite http://www.cyberciti.biz/faq/?p=10499 How do I auto Logout my shell user in Linux after certain minutes of inactivity?]]> http://www.cyberciti.biz/faq/linux-tmout-shell-autologout-variable/feed/ 0 UNIX / Linux: Increment The Datehttp://www.cyberciti.biz/faq/increment-the-date/ http://www.cyberciti.biz/faq/increment-the-date/#comments Tue, 26 Apr 2011 21:16:27 +0000 Vivek Gite http://www.cyberciti.biz/faq/?p=10450 I want to increment the date under UNIX or Linux operating system while writing shell scripts. For example Apr/27/2011 should be incremented as Apr/28/2011 and so on. How do I increment a date in UNIX or Linux shell?]]> http://www.cyberciti.biz/faq/increment-the-date/feed/ 1 Bash Remove Last Character From String / Line / Wordhttp://www.cyberciti.biz/faq/bash-remove-last-character-from-string-line-word/ http://www.cyberciti.biz/faq/bash-remove-last-character-from-string-line-word/#comments Tue, 26 Apr 2011 20:51:03 +0000 Vivek Gite http://www.cyberciti.biz/faq/?p=10444 I have a file of that looks as follows:
foo bar tom jerry UNIX Linux
Each word and/or Linux is a different length. How do strip or remove the last character from each line using bash or ksh shell only?]]> http://www.cyberciti.biz/faq/bash-remove-last-character-from-string-line-word/feed/ 3 Bash: Pass Shell Variables To awkhttp://www.cyberciti.biz/faq/linux-unix-appleosx-bsd-bash-passing-variables-to-awk/ http://www.cyberciti.biz/faq/linux-unix-appleosx-bsd-bash-passing-variables-to-awk/#comments Tue, 19 Apr 2011 20:07:49 +0000 Vivek Gite http://www.cyberciti.biz/faq/?p=10325 How do I pass shell variables to awk command or script under UNIX like operating systems?]]> http://www.cyberciti.biz/faq/linux-unix-appleosx-bsd-bash-passing-variables-to-awk/feed/ 0 Linux: Set Environment Variablehttp://www.cyberciti.biz/faq/set-environment-variable-linux/ http://www.cyberciti.biz/faq/set-environment-variable-linux/#comments Thu, 14 Apr 2011 12:18:34 +0000 Vivek Gite http://www.cyberciti.biz/faq/?p=10245 Bash shell is used for various purposes under Linux. How do I customize the shell environment variable under Linux operating systems?]]> http://www.cyberciti.biz/faq/set-environment-variable-linux/feed/ 4 Bash Shell: Extract Digits From a Stringhttp://www.cyberciti.biz/faq/linux-unix-bsd-shell-script-to-get-digits-from-string/ http://www.cyberciti.biz/faq/linux-unix-bsd-shell-script-to-get-digits-from-string/#comments Wed, 16 Feb 2011 10:56:41 +0000 Vivek Gite http://www.cyberciti.biz/faq/?p=10040 How do I extract digits only from a given string under Bash shell?]]> http://www.cyberciti.biz/faq/linux-unix-bsd-shell-script-to-get-digits-from-string/feed/ 9 Linux / UNIX: Bash Script Sleep or Delay a Specified Amount of Timehttp://www.cyberciti.biz/faq/linux-unix-sleep-bash-scripting/ http://www.cyberciti.biz/faq/linux-unix-sleep-bash-scripting/#comments Wed, 09 Feb 2011 20:31:57 +0000 Vivek Gite http://www.cyberciti.biz/faq/?p=9980 How do I pause for 5 seconds or 2 minutes in my bash shell script?]]> http://www.cyberciti.biz/faq/linux-unix-sleep-bash-scripting/feed/ 2 Howto: Call Shell Script function In echo statementhttp://www.cyberciti.biz/faq/unixlinux-bash-shell-script-function-call-in-echo-command/ http://www.cyberciti.biz/faq/unixlinux-bash-shell-script-function-call-in-echo-command/#comments Fri, 21 Jan 2011 19:07:23 +0000 Vivek Gite http://www.cyberciti.biz/faq/?p=9808 I need to call the function called foo() using echo command in the same statement. How do I all or invoke the function using the echo statement?]]> http://www.cyberciti.biz/faq/unixlinux-bash-shell-script-function-call-in-echo-command/feed/ 1 Bash Infinite Loop Exampleshttp://www.cyberciti.biz/faq/bash-infinite-loop/ http://www.cyberciti.biz/faq/bash-infinite-loop/#comments Thu, 20 Jan 2011 21:38:01 +0000 Vivek Gite http://www.cyberciti.biz/faq/?p=9791 How do I write an infinite loop in Bash script under Linux or UNIX like operating systems?]]> http://www.cyberciti.biz/faq/bash-infinite-loop/feed/ 2 Linux exec-notify: Find Out Shell Escaping Applications [ Security Monitoring ]http://www.cyberciti.biz/faq/linux-find-out-shell-escaping-applications-process/ http://www.cyberciti.biz/faq/linux-find-out-shell-escaping-applications-process/#comments Thu, 06 Jan 2011 13:14:04 +0000 Vivek Gite http://www.cyberciti.biz/faq/?p=9694 How do I watch or monitor applications that executed on a system and executes external programs via "bash"?]]> http://www.cyberciti.biz/faq/linux-find-out-shell-escaping-applications-process/feed/ 0 Linux / UNIX: Bash Loop Foreverhttp://www.cyberciti.biz/faq/bash-cycle-loop-forever/ http://www.cyberciti.biz/faq/bash-cycle-loop-forever/#comments Sat, 01 Jan 2011 21:36:13 +0000 Vivek Gite http://www.cyberciti.biz/faq/?p=10526 I need to cycles through a loop forever using for or while syntax. How do I set such loop under UNIX or Linux operating systems?]]> http://www.cyberciti.biz/faq/bash-cycle-loop-forever/feed/ 0