I was able to get a solution by looking at the curl doc which specifies to use – for the output to get the output to stdout. curl -o – -I http://localhost To get the response with just the http return code, I could just do curl -o /dev/null -s -w “%{http_code}\n” http://localhost
Try doing this using GNU sed: sed ‘/CLIENTSCRIPT=”foo”/a CLIENTSCRIPT2=”hello”‘ file if you want to substitute in-place, use sed -i ‘/CLIENTSCRIPT=”foo”/a CLIENTSCRIPT2=”hello”‘ file Output CLIENTSCRIPT=”foo” CLIENTSCRIPT2=”hello” CLIENTFILE=”bar” Doc see sed doc and search \a (append)
Don’t bother checking if the file exists, just try to remove it. rm -f /p/a/t/h # or rm /p/a/t/h 2> /dev/null Note that the second command will fail (return a non-zero exit status) if the file did not exist, but the first will succeed owing to the -f (short for –force) option. Depending on the … Read more
Here is a bash-only parser that leverages sed and awk to parse simple yaml files: function parse_yaml { local prefix=$2 local s=”[[:space:]]*” w='[a-zA-Z0-9_]*’ fs=$(echo @|tr @ ‘\034’) sed -ne “s|^\($s\):|\1|” \ -e “s|^\($s\)\($w\)$s:$s[\”‘]\(.*\)[\”‘]$s\$|\1$fs\2$fs\3|p” \ -e “s|^\($s\)\($w\)$s:$s\(.*\)$s\$|\1$fs\2$fs\3|p” $1 | awk -F$fs ‘{ indent = length($1)/2; vname[indent] = $2; for (i in vname) {if (i > indent) … Read more
In bash: #!/bin/bash echo before comment : <<‘END’ bla bla blurfl END echo after comment 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.
$? is used to find the return value of the last executed command. Try the following in the shell: ls somefile echo $? If somefile exists (regardless whether it is a file or directory), you will get the return value thrown by the ls command, which should be 0 (default “success” return value). If it … Read more
This is Bash-only: echo “${@: -1}”
Just to reiterate what has been posted for other shells, in Bash the following works: alias blah=”function _blah(){ echo “First: $1”; echo “Second: $2″; };_blah” Running the following: blah one two Gives the output below: First: one Second: two
From man 1 pkill -f The pattern is normally only matched against the process name. When -f is set, the full command line is used. Which means, for example, if we see these lines in ps aux: apache 24268 0.0 2.6 388152 27116 ? S Jun13 0:10 /usr/sbin/httpd apache 24272 0.0 2.6 387944 27104 ? … Read more
You can use shuf. On some systems at least (doesn’t appear to be in POSIX). As jleedev pointed out: sort -R might also be an option. On some systems at least; well, you get the picture. It has been pointed out that sort -R doesn’t really shuffle but instead sort items according to their hash … Read more