Getting Hostname in Bash in Linux

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In Bash, how to get the hostname of the node running the program? In Bash, you can get the hostname of the node in at least 2 ways: Use the variable $HOSTNAME. Get the hostname by command hostname. Get the content of /proc/sys/kernel/hostname Example: $ echo $HOSTNAME host01 $ hs=`hostname` $ echo $hs host01 $
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In Bash script, how to join multiple lines from a file?

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In Bash script, how to join multiple lines from a file? For example, to join the lines a good boy to a good boy You can use tr command, something like: tr -s ‘n’ ‘ ‘ < file.txt It just goes through its input and makes changes according to what you specify in two sets
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How to make tee catch the stderr only in Linux?

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I would like to make tee catch the stderr and log it into a file. A brute force method by let tee listen on both stderr and stdout is okay like cmd 2>&1 | tee -a log But how to make tee catch the stderr only? You can make use of “process substitution” (>(…)) to
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How to handle spaces in paths with rsync on Linux?

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The common rsync commands seems not handle spaces well. For example, rsync -avxP file “user@server:/data/my dir” It reports: rsync: link_stat “/home/zma/file” failed: No such file or directory (2) How to make rsync handle spaces well? You can use the –protect-args option of rsync. $ rsync –protect-args -avxP file “user@server:/data/my dir” What does –protect-args do: -s,
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How to install sshfs on CentOS 7?

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sshfs is a nice tool. But it seems there is no support to it in a newly installed CentOS 7 Linux system: Not installed by default: # sshfs -bash: sshfs: command not found Seems not available from the repositories # yum install sshfs -y Loaded plugins: fastestmirror Repodata is over 2 weeks old. Install yum-cron?
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How to get the full path and directory of a Makefile itself?

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How to get the full path and directory of a Makefile itself like finding Bash script’s own path? This 2 lines in Makefile get the full path and dir of the Makefile itself: mkfile_path := $(abspath $(lastword $(MAKEFILE_LIST))) mkfile_dir := $(dir $(mkfile_path)) The piece of code gets you Makefile, finds its absolute path and the
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How to test whether PATH has a specific directory in it in Bash on Linux?

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How to test whether PATH has a specific directory in it in Bash on Linux? For example, how to test whether /usr/local/mytool/bin is in $PATH? Directories in the $PATH variable are separated by :. So you can use a regular expression to test whether the $PATH contains a directory. The code for your specific example
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How to test a file or directory exists in Python?

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In Bash, the [ -f ] and [ -d ] tests can test whether a file or a directory exist. What are the corresponding python method for these tests? For -f: **os.path.isfile(path)** Return True if path is an existing regular file. This follows symbolic links. For -d: **os.path.isdir(path)** Return True if path is an existing
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