As pointed out by Max, you can’t, but checking files modified or accessed is not all that hard. I wrote a tutorial about this, as late as today. The essence of which is to use -newerXY and ! -newerXY: Example: To find all files modified on the 7th of June, 2007: $ find . -type … Read more
There are three approaches to finding the name of the current shell’s executable: Please note that all three approaches can be fooled if the executable of the shell is /bin/sh, but it’s really a renamed bash, for example (which frequently happens). Thus your second question of whether ps output will do is answered with “not … Read more
rm — –testings.html The — option tells rm to treat all further arguments as file names, not as options, even if they start with -. This isn’t particular to the rm command. The getopt function implements it, and many (all?) UNIX-style commands treat it the same way: — terminates option processing, and anything after it … Read more
Bash has built in features to access the last command executed. But that’s the last whole command (e.g. the whole case command), not individual simple commands like you originally requested. !:0 = the name of command executed. !:1 = the first parameter of the previous command !:4 = the fourth parameter of the previous command … Read more
Three best tricks shopt -s nullglob dotglob; f=your/dir/*; ((${#f})) This trick is 100% bash and invokes (spawns) a sub-shell. The idea is from Bruno De Fraine and improved by teambob‘s comment. files=$(shopt -s nullglob dotglob; echo your/dir/*) if (( ${#files} )) then echo “contains files” else echo “empty (or does not exist or is a … Read more
Use >> instead of > when directing output to a file: your_command >> file_to_append_to If file_to_append_to does not exist, it will be created. Example: $ echo “hello” > file $ echo “world” >> file $ cat file hello world
Using GNU sed: sed -i ‘$ d’ foo.txt The -i option does not exist in GNU sed versions older than 3.95, so you have to use it as a filter with a temporary file: cp foo.txt foo.txt.tmp sed ‘$ d’ foo.txt.tmp > foo.txt rm -f foo.txt.tmp Of course, in that case you could also use … Read more
EDIT – since Jul 23, 2015 The official postgres docker image will run .sql scripts found in the /docker-entrypoint-initdb.d/ folder. So all you need is to create the following sql script: init.sql CREATE USER docker; CREATE DATABASE docker; GRANT ALL PRIVILEGES ON DATABASE docker TO docker; and add it in your Dockerfile: Dockerfile FROM library/postgres … Read more
ternary operator ? : is just short form of if/else case “$b” in 5) a=$c ;; *) a=$d ;; esac Or [[ $b = 5 ]] && a=”$c” || a=”$d”
set -x or set -o xtrace expands variables and prints a little + sign before the line. set -v or set -o verbose does not expand the variables before printing. Use set +x and set +v to turn off the above settings. On the first line of the script, one can put #!/bin/sh -x (or … Read more