If you’re talking about the error message, you can suppress that by sending it to the bit bucket: cp ./src/*/*.h ./aaa 2>/dev/null If you want to suppress the exit code and the error message: cp ./src/*/*.h ./aaa 2>/dev/null || :
A single hyphen can be followed by multiple single-character flags. A double hyphen prefixes a single, multicharacter option. Consider this example: tar -czf In this example, -czf specifies three single-character flags: c, z, and f. Now consider another example: tar –exclude In this case, –exclude specifies a single, multicharacter option named exclude. The double hyphen … Read more
\b in regular expressions match word boundaries (i.e. the location between the first word character and non-word character):
Just make sure the python executable is in your PATH environment variable then add in your script Details: In the file job.sh, put this Execute this command to make the script runnable for you : chmod u+x job.sh Run it : ./job.sh
Not sure exactly how you want to use this, but here’s a basic example to get you started: To make it easier, you can alias the tr command in your .bashrc file thusly: Now you can just call:
The exec built-in command mirrors functions in the kernel, there are a family of them based on execve, which is usually called from C. exec replaces the current program in the current process, without forking a new process. It is not something you would use in every script you write, but it comes in handy on occasion. Here are some … Read more
If you’ve exported the environment variable: you can simply refer to it by name in the makefile (make imports all the environment variables you have set): If you’ve not exported the environment variable, it is not accessible until you do export it, or unless you pass it explicitly on the command line: If you are using a C … Read more
In bash: The ‘ and ‘ around the END delimiter are important, otherwise things inside the block like for example $(command) will be parsed and executed. For an explanation, see this and this question.
Problem is in your if [[…]] expression where you are using 2 grep commands without using command substitution i.e. $(grep ‘pattern’ file). However instead of: You can use grep -q: As per man grep:
You can use eval to execute a string: