Modern bash If you are running bash v4 or better, the PID of the subshell is available in $BASHPID. For example: $ echo $$ $BASHPID ; ( echo $$ $BASHPID ) 32326 32326 32326 1519 In the main shell, $BASHPID is the same as $$. In the subshell, it is updated to the subshell’s PID. … Read more
The easiest way to do it is a classic trick that’s been in the bourne shell for a while. for filename in `cat file_list`; do # Do stuff here done
Accrding to: http://www.vias.org/linux-knowhow/bbg_sect_08_02_01.html : -r If this option is given, backslash does not act as an escape character. The backslash is considered to be part of the line. In particular, a backslash-newline pair may not be used as a line continuation. It works on my machine. $ echo ‘\&|’ | while read -r in; do … Read more
You can use tr to delete all of the non-digit characters, like so: echo toto.titi.12.tata.2.abc.def | tr -d -c 0-9
Another (also rather ugly) option: ABSPATH=$(cd “$(dirname “$0″)”; pwd -P) From pwd man page, -P Display the physical current working directory (all symbolic links resolved).
You could do this purely in bash using the double square bracket [[ ]] test operator, which stores results in an array called BASH_REMATCH: [[ “TestT100String” =~ ([0-9]+) ]] && echo “${BASH_REMATCH[1]}”
$ echo “a\nb” a\nb $ echo -e “a\nb” a b
If you know that no filename contains newlines, use jq: ls | jq -R -s -c ‘split(“\n”)[:-1]’ Short explanation of the flags to jq: -R treats the input as string instead of JSON -s joins all lines into an array -c creates a compact output [:-1] removes the last empty string in the output array … Read more
When using –git-dir, you need to point at the .git folder of your repository. Try: git –git-dir=projectDirPath/.git show -s –pretty=format:%h The doc on –git-dir says that: –git-dir= Set the path to the repository (“.git” directory). This can also be controlled by setting the GIT_DIR environment variable. It can be an absolute path or relative path … Read more
If you are using Bash, you are better off using the arithmetic expression, ((…)) for readability and flexibility: if ((number >= 2 && number <= 5)); then # your code fi To read in a loop until a valid number is entered: #!/bin/bash while :; do read -p “Enter a number between 2 and 5: … Read more