scp Command Examples for Scripts

Q: What port option does scp use?

Capital -P: scp -P 2222 file host:/path/. ssh uses lowercase -p for the port, and scp's lowercase -p means preserve times and modes, so mixing them up silently changes what the command does. Putting Port 2222 under a Host entry in ~/.ssh/config avoids the difference entirely, because scp, ssh, sftp and rsync all read it.

Q: What does scp -O do?

-O forces the legacy SCP protocol instead of SFTP, which OpenSSH scp uses by default since version 9.0. You need it only for servers without an SFTP subsystem, such as some embedded devices and old appliances. Its main side effect is that remote paths are interpreted by the remote shell again, so spaces and wildcards need remote-side quoting, and file names are expanded by that shell.

Q: How do I check if scp succeeded in a bash script?

Test its exit status: if scp -q file host:/path/; then … else … fi, or capture rc=$? straight after. scp exits 0 on success, 1 on errors like a missing source or a permission problem on the remote side, and 255 when ssh cannot connect or authenticate. Exit 0 means the transfer completed, not that the remote copy is identical; for that, compare checksums on both ends as the script on this page does.

Copying the same files repeatedly?

Use rsync instead: Rsync Remote Backup has the script, and the Rsync Command Builder builds the command. Setting up the key scp uses is SSH Key Setup.

scp is the copy command everyone already knows, which is why its sharp edges survive in scripts for years. Since OpenSSH 9.0 it speaks SFTP by default, which quietly changed how remote paths are quoted, and -O brings the old rules back. -P is the port and -p is something else. And exit 0 means the transfer finished, not that the file on the other end is complete and correct, which matters for the backup that a cron job copies off the box every night.

What Are the scp Commands Worth Knowing?

Reproduced here on 2026-10-03 (Kali, OpenSSH 10.5p1) against a throwaway sshd listening on 127.0.0.1 port 2222, so nothing real was touched. demo is a ~/.ssh/config alias for it (below), and the remote directory, a scratch directory, is shown as /srv/drop.

text

$ scp report.csv demo:/srv/drop/
exit=0
$ scp demo:/srv/drop/report.csv ./copy.csv && cat copy.csv
id,total
1,9.50
exit=0
$ scp -r logs demo:/srv/drop/ && ssh demo ls /srv/drop/logs
a.log
b.log
exit=0

Upload, download, and a directory with -r. A trailing / on the remote side means "into this directory". -q (not used here) hides the progress bar, which you want in cron logs.

-p keeps the modification time, which backups and make-style "is it newer?" checks depend on:

text

$ scp notes.txt demo:/srv/drop/plain.txt; scp -p notes.txt demo:/srv/drop/kept.txt; ssh demo ls -l --time-style=+%F /srv/drop/plain.txt /srv/drop/kept.txt | cut -d" " -f6-
2026-09-01 /srv/drop/kept.txt
2026-10-03 /srv/drop/plain.txt
exit=0

Without -p the copy is stamped with the time of the copy. Lowercase -p is "preserve"; the port is capital -P. ssh uses lowercase -p for the port, so the two commands disagree, which is the best argument for the config alias.

The demo's alias, with its scratch paths shortened:

text

# ~/.ssh/config
Host demo
  HostName 127.0.0.1
  Port 2222
  IdentityFile ~/.ssh/demo_ed25519
  IdentitiesOnly yes

With that in place, scp, ssh, sftp and rsync all reach the server with the same short name and no flags to get wrong.

How Do I Copy Remote Paths With Spaces?

In the default SFTP mode, quote once for your own shell:

text

$ scp "my file.txt" "demo:/srv/drop/my file.txt" && ssh demo ls /srv/drop
kept.txt
logs
my file.txt
plain.txt
report.csv
exit=0

With -O, the legacy SCP protocol, the remote shell parses the path too, and splits it at the space:

text

$ scp -O "my file.txt" "demo:/srv/drop/legacy copy.txt"
scp: ambiguous target
exit=1
$ scp -O "my file.txt" "demo:'/srv/drop/legacy copy.txt'" && ssh demo ls /srv/drop
kept.txt
legacy copy.txt
logs
my file.txt
plain.txt
report.csv
exit=0

Double quoting (local quotes around remote quotes) is the old rule, and most scp tutorials written before 2022 teach it. It is now only for -O, which you need just for servers without an SFTP subsystem. Remote wildcards work in SFTP mode too; quote them so your local shell does not expand them first:

text

$ mkdir -p pulled && scp 'demo:/srv/drop/*.csv' pulled/ && ls pulled
report.csv
exit=0

What Exit Codes Does scp Return?

text

$ scp demo:/srv/drop/missing.csv .
scp: /srv/drop/missing.csv: No such file or directory
exit=1
$ scp -o ConnectTimeout=3 -P 2299 report.csv 127.0.0.1:/tmp/
ssh: connect to host 127.0.0.1 port 2299: Connection refused
scp: Connection closed
exit=255

1 is a file or permission problem; 255 is ssh failing to connect or authenticate. In a script that runs unattended, add -o BatchMode=yes so a missing key fails with 255 instead of waiting forever at a password prompt, and -o ConnectTimeout=10 so a dead host fails fast. Both codes, and what 255 means for ssh in general, are in the Bash Exit Code Lookup.

The Script

Exit 0 says the bytes were sent. It does not say the remote file matches, and a transfer killed halfway leaves a partial file under its real name for the next job to pick up. Save as scp-verified.sh: it uploads to a hidden .name.part, compares SHA-256 on both ends, and only then renames it into place.

bash

#!/bin/bash
# Script: scp-verified.sh
# Purpose: scp exits 0 without checking what arrived, and a copy cut off midway leaves a half file under the real name — this uploads to a temporary name, compares SHA-256 on both ends, then renames into place.
# Usage: ./scp-verified.sh HOST REMOTE_DIR FILE...   (HOST can be an ~/.ssh/config alias)
set -euo pipefail

CHECK="✓"
CROSS="✗"

[[ $# -ge 3 ]] || { echo "usage: $0 HOST REMOTE_DIR FILE..." >&2; exit 2; }
HOST="$1"
REMOTE_DIR="$2"
shift 2
# Options valid for both ssh and scp (-F, -i, -o …), e.g. SSH_OPTS="-F ./ssh_config"; put ports in ~/.ssh/config, since scp spells it -P and ssh -p. Word splitting is intended.
read -r -a SSH_OPTS <<< "${SSH_OPTS:-}"
FAILED=0

for f in "$@"; do
  if [[ ! -f "$f" ]]; then
    echo "$CROSS $f: not a regular file"
    FAILED=$((FAILED + 1))
    continue
  fi
  name=$(basename -- "$f")
  part="$REMOTE_DIR/.$name.part"
  local_sum=$(sha256sum -- "$f" | cut -d' ' -f1)

  # -p keeps the modification time; -q hides the progress bar so cron logs stay readable.
  rc=0
  scp "${SSH_OPTS[@]}" -p -q -- "$f" "$HOST:$part" || rc=$?
  if (( rc )); then
    echo "$CROSS $f: scp failed (exit $rc)"
    FAILED=$((FAILED + 1))
    continue
  fi

  # printf %q quotes the paths for the remote shell, so spaces and quotes in names survive.
  remote_sum=$(ssh "${SSH_OPTS[@]}" -n "$HOST" "sha256sum -- $(printf '%q' "$part")" | cut -d' ' -f1)
  if [[ "$remote_sum" != "$local_sum" ]]; then
    echo "$CROSS $f: checksum mismatch (local ${local_sum:0:12}, remote ${remote_sum:0:12}); left as $part"
    FAILED=$((FAILED + 1))
    continue
  fi

  # mv within one directory is an atomic rename: readers see the old file or the whole new one.
  ssh "${SSH_OPTS[@]}" -n "$HOST" "mv -f -- $(printf '%q' "$part") $(printf '%q' "$REMOTE_DIR/$name")"
  echo "$CHECK $f -> $HOST:$REMOTE_DIR/$name (sha256 ${local_sum:0:12}…)"
done

if (( FAILED )); then
  echo "$CROSS $FAILED file(s) not delivered"
  exit 1
fi

Prerequisites

OpenSSH client on your side; on the remote side, sshd plus sha256sum and mv (coreutils, present on every Linux server). Key-based login set up, ideally through a ~/.ssh/config alias.

How Does the Script Work?

.name.part is where the bytes land first. A transfer that dies leaves only a hidden temp file, never a truncated file under the real name.
sha256sum on both ends checks what actually arrived. scp's exit status cannot tell you that.
printf '%q' quotes paths for the remote shell, because the ssh … "command" calls run through it. That is why my file.txt below works without any manual double quoting.
ssh -n keeps those calls from reading the script's stdin, the same trap as an ssh call inside a while loop.
mv -f in the same directory is an atomic rename, so anything watching the drop directory sees a complete file appear.
FAILED counts problems without stopping the batch, and the exit code still reports them.

What Does the Script Print?

Three files, one with a space in its name, plus one that does not exist:

text

$ SSH_OPTS="-F ../ssh_config" ./scp-verified.sh demo /srv/drop report.csv db-dump.sql.gz "my file.txt" nope.txt
✓ report.csv -> demo:/srv/drop/report.csv (sha256 b53aab26f2c6…)
✓ db-dump.sql.gz -> demo:/srv/drop/db-dump.sql.gz (sha256 0590d7be2176…)
✓ my file.txt -> demo:/srv/drop/my file.txt (sha256 98ea6e4f216f…)
✗ nope.txt: not a regular file
✗ 1 file(s) not delivered
exit=1
$ ssh demo ls -la /srv/drop | grep -E "db-dump|part|report"
-rw-rw-r-- 1 travis travis 2097152 Oct  3 16:19 db-dump.sql.gz
-rw-rw-r-- 1 travis travis      16 Oct  3 16:19 report.csv

No .part files left behind. (SSH_OPTS points at the demo's own config file; with the alias in ~/.ssh/config you would leave it out.)

When Should I Use rsync Instead?

Every scp run copies every byte again. rsync compares first and sends only what changed, resumes with --partial, checksums each file as part of the transfer, and mirrors deletions with --delete. For a nightly copy of a backup directory that is the difference between minutes and seconds, and between a broken half-copy and a resumed one. Rsync Remote Backup is the script for that; Run Commands on a Remote Server over SSH covers what to do once the file is there. The Production Bash Toolkit ships its scripts ShellCheck-clean.

Frequently Asked Questions

How do I scp a file with spaces in the name?

With OpenSSH 9.0 or later in its default SFTP mode, quote the whole argument once for your local shell: scp "my file.txt" "host:/srv/drop/my file.txt". With scp -O, the legacy protocol, the remote path is also parsed by the remote shell, so it needs a second set of quotes inside: "host:'/srv/drop/my file.txt'". Without them, -O fails with scp: ambiguous target.

What port option does scp use?

Capital -P: scp -P 2222 file host:/path/. ssh uses lowercase -p for the port, and scp's lowercase -p means preserve times and modes, so mixing them up silently changes what the command does. Putting Port 2222 under a Host entry in ~/.ssh/config avoids the difference entirely, because scp, ssh, sftp and rsync all read it.

What does scp -O do?

-O forces the legacy SCP protocol instead of SFTP, which OpenSSH scp uses by default since version 9.0. You need it only for servers without an SFTP subsystem, such as some embedded devices and old appliances. Its main side effect is that remote paths are interpreted by the remote shell again, so spaces and wildcards need remote-side quoting, and file names are expanded by that shell.

How do I check if scp succeeded in a bash script?

Test its exit status: if scp -q file host:/path/; then … else … fi, or capture rc=$? straight after. scp exits 0 on success, 1 on errors like a missing source or a permission problem on the remote side, and 255 when ssh cannot connect or authenticate. Exit 0 means the transfer completed, not that the remote copy is identical; for that, compare checksums on both ends as the script on this page does.

Should I use scp or rsync?

Use scp for a one-off copy of a few files. Use rsync for anything repeated or large: it sends only files and blocks that changed, can resume an interrupted transfer with --partial, verifies each file with a checksum as part of the transfer, and can delete files that disappeared from the source with --delete. Both run over ssh and read the same ~/.ssh/config, so switching is usually a one-word change.

Part of the bash snippets collection

Rsync Remote Backup — repeated or large copies, only the changes sent
SSH Key Setup — the key scp and the script authenticate with
Run Commands on a Remote Server over SSH — what to run once the file has arrived
Bash Heredoc — sending a whole script to the remote side

scp Command Examples for Scripts: Push, Pull, Spaces, -O and Exit Codes

What Are the scp Commands Worth Knowing?

How Do I Copy Remote Paths With Spaces?

What Exit Codes Does scp Return?

The Script

Prerequisites

How Does the Script Work?

What Does the Script Print?

When Should I Use rsync Instead?

Frequently Asked Questions

How do I scp a file with spaces in the name?

What port option does scp use?

What does scp -O do?

How do I check if scp succeeded in a bash script?

Should I use scp or rsync?

The Production Bash Toolkit

Get the bashlib starter

Related Snippets

Frequently Asked Questions

scp Command Examples for Scripts: Push, Pull, Spaces, -O and Exit Codes

What Are the scp Commands Worth Knowing?

How Do I Copy Remote Paths With Spaces?

What Exit Codes Does scp Return?

The Script

Prerequisites

How Does the Script Work?

What Does the Script Print?

When Should I Use rsync Instead?

Frequently Asked Questions

How do I scp a file with spaces in the name?

What port option does scp use?

What does scp -O do?

How do I check if scp succeeded in a bash script?

Should I use scp or rsync?

Related Scripts

The Production Bash Toolkit

Get the bashlib starter

Related Snippets

Frequently Asked Questions