How to make Evolution not wrap lines in composed Emails?

Evolution seems wrap long lines automatically in “Plain Text” mode. How to make Evolution not wrap lines in composed Emails? Evolution does not have (so far) “Flowing Text” mode where “the text is soft broken at the composer edge, but those soft breaks aren’t translated to hard breaks when the mail is sent” ( Reference: […]

How to enable Email address auto completion in Evolution?

Does Evolution support automatic email address filling/completing in the “To” or “CC” fields which is commonly seen in other Email clients such as Thunderbird. Is is possible and how to enable Email address auto completion in Evolution? Evolution supports the contact autocompletion. To enable it, do as follows in Evolution. In Evolution Preferences dialog, in […]

How to remove newline characters from a string in C++?

How to remove newline characters from a string in C++? For example, a string like line 1 line 3 line 4 should be converted to line 1line 3line 4 In short, use this code snippet: input.erase(std::remove(input.begin(), input.end(), ‘n’), input.end()); std::remove() shifts all elements that are equal to the value n by moving the elements in […]

How to split a string by string in Bash?

How to split a string by string in Bash? For example, “a string separated by space” => [“a”, “string”, “separated”, “by”, “space”] and “a,string,separated,by,comma” => [“a”, “string”, “separated”, “by”, “comma”] You can convert a string to an array using the grammar like inarr=(${a}) If the delimiter is not space and delimiter is a single character […]

How to make Ubuntu Linux boot to text mode?

My Ubuntu boots to GUI mode by default. How to make Ubuntu Linux boot to text mode? If you are using Ubuntu older than 16 such as Ubuntu 14.04: Edit /etc/default/grub Change GRUB_CMDLINE_LINUX=… to GRUB_CMDLINE_LINUX=”text”. Backup your old grub config`$ sudo cp -n /etc/default/grub /etc/default/grub.bak-date +%s ` Update grub$ sudo update-grub If you are using […]

How to encode spaces in curl GET request URL on Linux?

The problem is like this: I would like to send a GET request using curl and the content has spaces, such as curl “http://example.com/send?msg=hello world” The space and the “world” will be left away if this command is executed directory on Linux. How to encode spaces in curl request URL? You can use the –date-urlencode […]

How to get the directory path and file name from a absolute path in Bash on Linux?

How to get the directory path and file name from a absolute path in Bash on Linux? For example, with “/foo/bar/baz.txt”, it will produce: “/foo/bar/” and “baz.txt”. You also have the basename and dirname commands besides of the basename and dirname C API in Linux: [zma@laptop:~]$ p=”/foo/bar/baz.txt” [zma@laptop:~]$ dirname $p /foo/bar [zma@laptop:~]$ basename $p baz.txt […]

How to redirect STDOUT of sudo command on Linux and write to file as root?

A try like the following command failed $ sudo echo “echo hello” > /usr/local/bin/hello with an message bash: /usr/local/bin/hello: Permission denied It seems the writing to the file is executed under the non-root user. How to redirect STDOUT of sudo command on Linux and write the content to the file (/usr/local/bin/hello here) as root? You […]

How to delete a specific line from a text file in command line on Linux?

On Linux, how to delete a specific line from a text file in command line? For example, to delete the 4th line from a file aaa bbb ccc ddd eee ffffff You can use the “stream editor for filtering and transforming text” sed. With GNU sed: sed -i ‘4d’ ./file Here, -i means edit the […]

How to calculate the average of value in lines of a text file on Linux by a script?

How to calculate the average of value in lines of a text file on Linux by a script? The file.txt is like: Run 0: Time used: 22.235331711 seconds. Run 1: Time used: 20.784491219 seconds. Run 2: Time used: 21.851638876 seconds. What I want it to calculate the average time. awk is handy for this purpose: […]