This question already has answers here:
How to cat multiple files from a list of files in Bash?
(6 answers)
Closed 4 years ago.
How should i concatenate multiple text files get by arguments in terminal using a script in Bash?
#!/bin/bash
while read $1
do
cat $1 > cat.txt
done
I tried that example but it is not working.
You should use '>>' to concatenate ('>' will create a new file each time):
for file in "$#"
do
cat $file >> result
done
Related
This question already has answers here:
Script parameters in Bash
(5 answers)
How do I parse command line arguments in Bash?
(40 answers)
Closed 2 years ago.
I made a .sh file with a program, the current input is as follows:
$ ./myprogram.sh
file.txt
How can I make it so the input is as follows instead:
$ ./myprogram.sh file.txt
Inside the shell script, you can refer to the arguments by their positions as $1, $2, etc. Note that the arguments start at 1, and $0 is the name of the executed script. $# contains the total number of arguments.
This question already has answers here:
Capturing multiple line output into a Bash variable
(7 answers)
Closed 3 years ago.
I have a small script where I appended the output of linux mpstat to a log file.
#/bin/bash
CPU_USAGE=$(mpstat)
echo $CPU_USAGE >> temp.log
The problem is that the output of mpstat on the terminal is formatted properly in 3 lines like so
However, the output to the file is all in one line.
How do I format the output like the one on the terminal?
Just quote the variable so it is not seen as several different parameters to be printed one after the other:
echo "$CPU_USAGE" >> temp.log
You could just directly pipe the output to the file:
#!/bin/bash
mpstat >> temp.log
If you must store it in a variable, then quote it like:
#!/bin/bash
CPU_USAGE=$(mpstat)
echo "$CPU_USAGE" >> temp.log
Otherwise, bash will not interpret the newlines as part of the message to echo, but the whole output as a list of short strings to output.
This question already has answers here:
Use key/value data from a file in a shell script
(1 answer)
Reading key/value parameters from a file into a shell script
(1 answer)
Closed 3 years ago.
$ cat foo.txt
a=1one
b=2two
c=3 three
d=4four
$ source foo.txt
bash: three: command not found...
Need to set all the variable listed in foo.txt, how to source this file by escaping the space character? foo.txt comes from other application, which I cannot control, or is there an alternative to source ?
If the output is so regular, you could try to preprocess the file using sed like this:
$ sed -e "s/=/='/;s/$/'/" < foo.txt >sourced.env
and then source sourced.env. This will add a ' just after the = and add an ending '.
This question already has answers here:
Looping over pairs of values in bash [duplicate]
(6 answers)
Closed 5 years ago.
I have some files in a directory "documents" (file1, file2, ...) and I would like to save them in another directory "documents_hex" with hexdump from command line. There is a way to use hexdump for each file in "documents" and save them in "documents_hex" ("documents_hex" is inside "documents") with the same name in input and output?
Example: file1 to /documents_hex/file1, file2 to /documents_hex/file2, ...
Check this code :
for file in `ls documents`
do
hexdump -x $file > documents_hex/$file
done
This question already has answers here:
Capturing multiple line output into a Bash variable
(7 answers)
Closed 5 years ago.
I'm trying to capture a block of text into a variable, with newlines maintained, then echo it.
However, the newlines don't seemed to be maintained when I am either capturing the text or displaying it.
Any ideas regarding how I can accomplish this?
Example:
#!/bin/bash
read -d '' my_var <<"BLOCK"
this
is
a
test
BLOCK
echo $my_var
Output:
this is a test
Desired output:
this
is
a
test
You need to add " quotes around your variable.
echo "$my_var"