Tagged Questions
2
votes
2answers
90 views
$BASHPID And $$ differ in some cases
I'm reading "BASH pocket guide of Oreilly".
It said:
The process ID of the current Bash process.
In some cases, this can differ from $$.
Above explanation , explained $BASHPID variable.
...
2
votes
2answers
68 views
Parameter expansion seems to be missing a piece
I'm currently learning how to write simple scripts and can't get my head around a very simple problem.
I have the following command in my script...
touch ${DIRECTORY}/${FILE}
This command appears ...
2
votes
2answers
105 views
Parameter splitting
I have a bash script that is a simple wrapper around another process:
$ cat ~/bin/s3cmd
#!/bin/sh
trickle -u 80 ~/bin/s3cmd.py $*
$
This works great when the parameters don't contain spaces. ...
3
votes
2answers
167 views
Function caller positional parameters
I need to read and write the positional parameters $@ of a function's caller. The Bash man page says that:
A shell function is an object that is called like a simple command and
executes a ...
1
vote
2answers
184 views
Transforming positional arguments of a shell script
I'm trying to write a shell script that will transform positional
arguments that are passed to it as follows.
The shell script passes these arguments to a binary executable
(ffigen) which is derived ...
3
votes
2answers
135 views
how to make getopts just read the first character post `-`
I have a shell script testShell.sh which uses getopts as below:
#!/bin/bash
while getopts ":j:e:" option; do
case "$option" in
j) MYHOSTNAME=$OPTARG ;;
e) SCRIPT_PATH=$OPTARG ;;
...
3
votes
1answer
127 views
How can I pipe a path to pushd?
This seems like it should be easy enough to do, but I'm clearly not understanding something fundamental about piping output back and forth.
I'm trying to do something like this:
bundle show ...
7
votes
2answers
581 views
What does `:-` mean in a shell script
I saw this in the end of an awesome shell script but I can't understand the login here because I think it's being short-handed for a longer command.
spark ${@:-`cat`}
This apears at the end of this ...
3
votes
2answers
267 views
Getopts option processing, Is it possible to add a non hyphenated [FILE]?
I'm using getopts for all of my scripts that require advanced option parsing, and It's worked great with dash. I'm familiar with the standard basic getopts usage, consisting of [-x] and [-x OPTION]. ...
5
votes
1answer
4k views
How to check if there are no parameters provided to a command?
How do you check if $* is empty? In other words, how to check if there were no arguments provided to a command?
10
votes
1answer
377 views
How do ${0##*/} and ${0%/*} work?
I'm quite confused about the following regular expressions I found in a shell script:
${0##*/}
${0%/*}
How do they work?
2
votes
1answer
157 views
How to unset the positional parameters?
How do I do this:
set foo bar baz
unset # Something else here
echo $# # Should ouput 0
By doing set "", $# will still be 1 and not 0.
2
votes
2answers
470 views
How to escape < or > in a parameter in shell?
I'd like to use grep with a PCRE expression that contains the < character. Bash thinks I want to redirect, but I don't want to. How can I escape <?
2
votes
2answers
154 views
Want a seperate file to store mysql username, password, and database name
I have as script that dumps a mysql database, and compresses the file. What I want to do is have another (edit) file which can change the username, password and database name. Then somehow connecting ...
16
votes
3answers
4k views
How to pass parameters to an alias?
For bash script, I can use "$@" to access arguments. What's the equivalent when I use an alias?
