# this works: rm foo # versus this, which doesn’t: rm foo/ Basically, you need to tell it to delete a file, not delete a directory. I believe the difference between rm and rmdir exists because of differences in the way the C library treats each. At any rate, the first should work, while the … Read more
There are a wealth of clipboards you could be dealing with. I expect you’re probably a Linux user who wants to put stuff in the X Windows primary clipboard. Usually, the clipboard you want to talk to has a utility that lets you talk to it. In the case of X, there’s xclip (and others). … Read more
This fuser 8080/tcp will print you PID of process bound on that port. And this fuser -k 8080/tcp will kill that process. Works on Linux only. More universal is use of lsof -i4 (or 6 for IPv6).
Run this query from PostgreSQL: SELECT version();
Data Storage: Specify the utf8mb4 character set on all tables and text columns in your database. This makes MySQL physically store and retrieve values encoded natively in UTF-8. Note that MySQL will implicitly use utf8mb4 encoding if a utf8mb4_* collation is specified (without any explicit character set). In older versions of MySQL (< 5.5.3), you’ll … Read more
Use wc: wc -l <filename> This will output the number of lines in <filename>: $ wc -l /dir/file.txt 3272485 /dir/file.txt Or, to omit the <filename> from the result use wc -l < <filename>: $ wc -l < /dir/file.txt 3272485 You can also pipe data to wc as well: $ cat /dir/file.txt | wc -l 3272485 … Read more
The standard option grep -l (that is a lowercase L) could do this. From the Unix standard: -l (The letter ell.) Write only the names of files containing selected lines to standard output. Pathnames are written once per file searched. If the standard input is searched, a pathname of (standard input) will be written, in … Read more
The option you’re looking for is -R. cp -R path_to_source path_to_destination/ If destination doesn’t exist, it will be created. -R means copy directories recursively. You can also use -r since it’s case-insensitive. To copy everything inside the source folder (symlinks, hidden files) without copying the source folder itself use -a flag along with trailing /. … Read more
The command you want is named tee: foo | tee output.file For example, if you only care about stdout: ls -a | tee output.file If you want to include stderr, do: program [arguments…] 2>&1 | tee outfile 2>&1 redirects channel 2 (stderr/standard error) into channel 1 (stdout/standard output), such that both is written as stdout. … Read more
Considering that pdfunite is part of poppler it has a higher chance to be installed, usage is also simpler than pdftk: pdfunite in-1.pdf in-2.pdf in-n.pdf out.pdf Just make sure you remember to provide out.pdf, or else it will overwrite the last file in your command