使用 adb 从手机相机传输照片的脚本

Question

Story

I take photos and record videos with my phone camera and keep all of them on my internal storage/sdcard. I periodically back them up on my PC, so I keep these camera photos on PC storage in sync with phone storage.

For years, I've been backing up my phone camera photos to my PC in the following way:

1. Plug in phone into PC and allow access to phone data
2. Browse phone storage → DCIM → Camera
3. Wait several minutes for the system to load a list of ALL photos
4. Copy only several latest photos which haven't been backed up yet

I figured that waiting several minutes for all photos to load is an unnecessary drag so I downloaded adb platform tools . I've added the folder bin to my Path environment variable (ie %USERPROFILE%\\Tools\\adb-platform-tools_r28.0.3 ) so that I can seamlessly use adb and not write its full path each time.

The script

I wrote the following script for Git Bash for Windows. It is also compatible with Unix if you change the $userprofile variable. Essentially, the script pulls camera photos between two dates from phone storage to PC .

# Attach device and start deamon process
adb devices

# Initialize needed variables
userprofile=$(echo "$USERPROFILE" | tr "\\" "/") # Windows adjustments

srcFolder="//storage/06CB-C9CE/DCIM/Camera"    # Remote folder
dstFolder="$userprofile/Desktop/CameraPhotos"  # Local folder
lsFile="$dstFolder/camera-ls.txt"
filenameRegex="2019061[5-9]_.*"  # Date from 20190615 to 20190619

# Create dst folder if it doesn't exist
mkdir -p "$dstFolder"

# 1. List contents from src folder
# 2. Filter out file names matching regex
# 3. Write these file names line by line into a ls file
adb shell ls "$srcFolder" | grep -E "$filenameRegex" > "$lsFile"

# Pull files listed in ls file from src to dst folder
while read filename; do
  if [ -z "$filename" ]; then continue; fi
  adb pull "$srcFolder/$filename" "$dstFolder" # adb: error: ...
done < "$lsFile"

# Clean up
rm "$lsFile"

# Inform the user
echo "Done pulling files to $dstFolder"

The problem

When I run the script ( bash adb-pull-camera-photos.sh ), everything runs smoothly except for the adb pull command in the while -loop. It gives the following error :

': No such file or directoryemote object '//storage/06CB-C9CE/DCIM/Camera/20190618_124656.jpg
': No such file or directoryemote object '//storage/06CB-C9CE/DCIM/Camera/20190618_204522.jpg
': No such file or directoryemote object '//storage/06CB-C9CE/DCIM/Camera/20190619_225739.jpg

I am not sure why the output is broken. Sometimes when I resize the Git Bash window some of the text goes haywire. This is the actual error text:

adb: error: failed to stat remote object '//storage/06CB-C9CE/DCIM/Camera/20190618_124656.jpg': No such file or directory
adb: error: failed to stat remote object '//storage/06CB-C9CE/DCIM/Camera/20190618_204522.jpg': No such file or directory
adb: error: failed to stat remote object '//storage/06CB-C9CE/DCIM/Camera/20190619_225739.jpg': No such file or directory

I am sure that these files exist in the specified directory on the phone. When I manually execute the failing command in bash, it succeeds with the following output :

$ adb pull "//storage/06CB-C9CE/DCIM/Camera/20190618_124656.jpg" "C:/Users/User/Desktop/CameraPhotos/"
//storage/06CB-C9CE/DCIM/Camera/20190618_124656.jpg: 1 file pulled. 15.4 MB/s (1854453 bytes in 0.115s)

The question

I can't figure out what's wrong with the script. I thought the Windows system might be causing a commotion, because I don't see the reason why the same code works when entered manually, but doesn't work when run in a script. How do I fix this error?

Additional info

• Note that I had to use // in the beginning of an absolute path on Windows because Git Bash would interpret / as its own root directory ( C:\\Program Files\\Git ).
• I've echo ed all variables inside the script and got all the correct paths that otherwise work via manual method.

camera-ls.txt file contents

20190618_124656.jpg
20190618_204522.jpg
20190619_225739.jpg

Additional questions

1. Is it possible to navigate to external sdcard without using its name? I had to use /storage/06CB-C9CE/ because /sdcard/ navigates to internal storage.
2. Why does tr "\\\\" "/" give me this error: tr: warning: an unescaped backslash at end of string is not portable ?

Answer 1

The problem was with Windows line delimiters .

Easy fix

Just add the IFS=$'\\r\\n' above the loop so that the read command knows the actual line delimiter.

IFS=$'\r\n'
while read filename; do
  if [ -z "$filename" ]; then continue; fi
  adb pull "$srcFolder/$filename" "$dstFolder"
done < "$lsFile"

Explanation

I tried plugging the whole while -loop into the console and it failed with the same error:

$ bash adb-pull-camera-photos.sh
List of devices attached
9889db343047534336      device

tr: warning: an unescaped backslash at end of string is not portable
': No such file or directoryemote object '//storage/06CB-C9CE/DCIM/Camera/20190618_124656.jpg
': No such file or directoryemote object '//storage/06CB-C9CE/DCIM/Camera/20190618_204522.jpg
': No such file or directoryemote object '//storage/06CB-C9CE/DCIM/Camera/20190619_225739.jpg
Done pulling files to C:/Users/User/Desktop/CameraPhotos

This time I started investigating why the output was broken . I remembered that windows uses \\r\\n as newline, which means Carriage Return + Line Feed, (CR+LF) , so some text must have been overwritten.

It was because of broken values stored inside the $filename variable.

This is the loop from the script:

while read filename; do
  if [ -z "$filename" ]; then continue; fi
  adb pull "$srcFolder/$filename" "$dstFolder"
done < "$lsFile"

Since each iteration of the while -loop reads a line from $lsFile in the following form:

exampleFilename.jpg\r\n

It misinterprets the newline symbols as part of the file name, so adb pull tries to read files with these whitespaces in their names, but fails and it additionally writes a broken output.

Answer 2

Windows batch script

Here's a .bat script that can be run by Windows Command Prompt or Windows PowerShell . No Git Bash required.

:: Start deamon of the device attached
adb devices

:: Pull camera files starting from date
set srcFolder=/storage/06CB-C9CE/DCIM/Camera
set dstFolder=%USERPROFILE%\Desktop\CameraPhotos
set lsFile=%USERPROFILE%\Desktop\CameraPhotos\camera-ls.txt
set dateRegex=2019061[5-9]_.*

mkdir %dstFolder%
adb shell ls %srcFolder% | adb shell grep %dateRegex% > %lsFile%
for /F "tokens=*" %%A in (%lsFile%) do adb pull %srcFolder%/%%A %dstFolder%
del %lsFile%
echo Done pulling files to %dstFolder%

• Just edit the srcFolder to point to your phone camera folder,
• plug a pattern into the dateRegex for matching the date interval and
• save it as a file with .bat extension, ie: adb-pull-camera-photos.bat .
• Double-click the file and it will pull filtered photos into CameraPhotos folder on Desktop.

Keep in mind that you still need have adb for Windows on your PC.

Answer 3

Adb Photo Sync

This might not be the answer but might be useful for others looking for android photo/files backup solution.

I use this script on my Windows with git bash. This can be easily used for Linux. A common issue with a long backup process is that it might get interrupted and you might have to restart the entire copy process from start.

This script saves you from this trouble. You can restart the script or interrupt in between but it will resume copy operation from the point it left.

Just change the rfolder => android folder, lfolder => local folder

#!/bin/sh

rfolder=sdcard/DCIM/Camera
lfolder=/f/mylocal/s8-backup/Camera

adb shell ls "$rfolder" > android.files

ls -1 "$lfolder" > local.files

rm -f update.files
touch update.files

while IFS=  read -r q; do
  # Remove non-printable characters (are not visible on console)
  l=$(echo ${q} | sed 's/[^[:print:]]//')
  # Populate files to update
  if ! grep -q "$l" local.files; then         
    echo "$l" >> update.files
  fi  
done < android.files

script_dir=$(pwd)
cd $lfolder

while IFS=  read -r q; do
  # Remove non-printable characters (are not visible on console)
  l=$(echo ${q} | sed 's/[^[:print:]]//')
  echo "Get file: $l"
  adb pull "$rfolder/$l"
done < "${script_dir}"/update.files