Questions tagged [here-document]
The here-document tag has no summary.
242 questions
0
votes
0
answers
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bash variable substitution inside heredoc delimiter: how does it work? [duplicate]
For a school project, I am tasked with making my own (simplified) shell, with bash being the reference point. This includes replicating heredoc behavior which was fun until I stumbled upon variable ...
- 101
2
votes
1
answer
251
views
Using Here-Document as password Input for ssh
First, I do know this is a security risk. I do know about ssh keys and sshpass. This belongs to a fun project.
I wondered if a bash Here-Document could be used as a password input for ssh.
I ...
7
votes
2
answers
862
views
Is it possible to define a bash heredoc with a multi-word delimiter that expands variables?
Consider the following script:
#!/bin/bash
foo=Hello
bar=Word
cat <<EOF
No quotes single word delimiter expands
$foo
$bar
EOF
cat <<'EOF'
Single-quoted single word delimiter does not ...
- 4,179
8
votes
1
answer
910
views
Why does bash with "here documents" redirection start as interactive?
I found the following in man bash as a definition of interactive shell:
An interactive shell is one started without non-option arguments
(unless -s is specified) and without the -c option whose ...
- 517
0
votes
1
answer
86
views
How can I use a here-document on the left-hand side of a pipeline? [duplicate]
Show lines passed by here-document in the stdout:
cat <<EOF
foo
bar
baz
EOF
foo
bar
baz
I want to match some string with grep via pipe:
cat <<EOF
foo
bar
baz
EOF
|grep 'ba'
Why can't ...
- 571
6
votes
3
answers
1k
views
How can I assign a heredoc to a variable in a way that's portable across Unix and Mac?
This code works fine on Linux but not Mac OS:
#!/usr/bin/env bash
foo=$(cat <<EOF
"\[^"\]+"
EOF
)
printf "%s" "$foo"
It fails on Mac with
./test.sh: line 6: ...
- 183
0
votes
2
answers
161
views
Cat file and heredoc to pipe
I do some automatic checks and want to send a mail if a file has changed. I want the mail body to contain the new version of the file, some static text and the old version of the file, so what I do is
...
- 1,443
11
votes
1
answer
1k
views
Bash 4: unexpected EOF while looking for matching `)'
This very simplified version of my script
#!/usr/bin/env bash
example="$(bash -rs <<'BASH' -- 'This has been executed in restricted shell'
echo "$1"
BASH
)"
echo "$...
- 121
5
votes
3
answers
2k
views
"Here Document" as a Single Line Command?
I have this command to run a checksum in some software I want to install:
echo "85762db0edc00ce19a2cd5496d1627903e6198ad850bbbdefb2ceaa46bd20cbd install.sh" | sha256sum -c
But I would like ...
- 51
5
votes
1
answer
331
views
How can I pass variables to a file printed from outside a bash script?
Assuming I have a variable v="c d e f g" and a file with the content:
line1
$v
line3
How can I make a bash script print this file with the content of the variable in line 2 as if I was ...
- 6,094
0
votes
1
answer
131
views
How to combine ...if $x and a here-doc in perl? [closed]
How is one supposed to write this?
print <<EOF; if $x
bla
EOF
I think it is called postfix notation, and a here-doc. I get a syntax error.
OK, I guess I'll just use
print "bla" if $x;
...
- 570
0
votes
2
answers
85
views
Testing for dir via ssh script - nothing happens
I usually run server scripts like this, with a here-document.
But when I test if a directory exists, the script continues even though the test fails -- why?
ssh $user@$ip /bin/bash <<SCRIPT
if [...
- 236
0
votes
0
answers
873
views
How to use heredoc inside my ssh command
I have a bash script that connects to a remote machine via SSH and runs a series of commands.
It seems that the heredoc within the outer script is not aligning properly, and I keep getting an error.
-...
- 1,927
0
votes
2
answers
160
views
How to pass a script-file to sed as a heredoc?
This converts 'a' to 'A'.
sed 's/a/A/g' <(echo "foobar")
foobAr
This supplies the commands necessary to make each vowel upper-case:
$ cat << EOF
s/a/A/g
s/e/E/g
s/i/I/g
s/o/O/g
s/u/...
- 729
0
votes
1
answer
1k
views
How can I supply a heredoc to podman run?
When I run buildah, I typically use a heredoc,
ctr=$(buildah from alpine:3);
buildah run $ctr sh -- <<EOF
apk update;
apk add git;
EOF
buildah commit $ctr heredoc_demo;
However, when I ...
- 35.1k