問題
在工作中會遇到需要模擬存儲空間不足的場景,以驗證某功能點或復現某些特殊bug。常規做法是通過手工拷貝大文件到測試設備,模擬存儲空間不足,當涉及機型適配時得在N個設備重復操作N次,手工操作非常繁瑣,該如何高效解決這個問題呢?
解決方案
是否有方法可以模擬設備存儲空間不足的場景,此時聯想到adb shell dd命令就可以很好地實現我們的需求,它支持生成指定大小的塊文件,具體命令和參數解釋如下
adb shell dd命令
adb shell dd if=/dev/zero of=/sdcard/tmp/auto_dd_file bs=1024 count=1
據寫入的文件,而不在標准輸出顯示
###參數含義
if=文件:讀取內容,而非標准輸入的數據
of=文件:將數
bs=bytes:同時設置讀入/輸出的塊大小為bytes字節,未填寫時默認512 bytes
ibs:一次讀入bytes個字節,即指定一個塊大小為bytes字節
obs=bytes:一次輸出bytes個字節,即指定一個塊大小為bytes字節。
count :創建/拷貝blocks個數,塊大小等於bs指定的字節數。
注:單位是byte,如需要1000M大文件,bs=1024*1024*100,單位不支持M或Kb
如果要生成一個10M和20M文件,可以這樣使用
C:\Users\zhongyaqi>adb shell dd if=/dev/zero of=/sdcard/tmp/auto_dd_file1 bs=102
4*1024*10 count=1
1+0 records in
1+0 records out
10485760 bytes transferred in 0.042 secs (249660952 bytes/sec)
C:\Users\zhongyaqi>adb shell dd if=/dev/zero of=/sdcard/tmp/auto_dd_file2 bs=102
4*1024*10 count=2
2+0 records in
2+0 records out
20971520 bytes transferred in 0.081 secs (258907654 bytes/sec)
驗證執行結果,在/sdcard/tmp/目錄下生成了10M和20M的文件
C:\Users\zhongyaqi>adb shell
PD1709:/ $ cd /sdcard/tmp/
cd /sdcard/tmp/
PD1709:/sdcard/tmp $ ls -l -h
ls -l -h
total 131M
-rw-rw---- 1 root sdcard_rw 10M 2020-04-25 17:11 auto_dd_file1
-rw-rw---- 1 root sdcard_rw 20M 2020-04-25 17:11 auto_dd_file2
Python腳本實現
在上一篇文章中,實現批量復制文件前,進行了檢查adb連接狀態等操作,同樣該該操作也適用於本篇文章使用的場景,有興趣的請參考Python腳本葵花寶典之一鍵批量復制文件
def run_create_file(self, byte, count, path):
"""
:param byte: The unit is byte
:param count: Number of blocks created
:param path: THE path of file that includes file name
:return:
for example
byte = 1024*1024*100
count = 1
path = '/sdcard/tmp/test_dd'
"""
print("step2 Create file and check status")
ADB_SHELL_DD = "adb shell dd if=/dev/zero of=%s bs=%d count=%d " % (path,byte,count)
os.system(ADB_SHELL_DD)
adbfile = os.popen(ADB_SHELL_DD, "r")
result = adbfile.read()
if "%s bytes transferred in" % str(byte) in result:
print("Create file success,file size is %sM ,and file path is %s " % (str(byte/1024/1024),path))
else:
print("Create file failed\n")
腳本執行結果如下
step1 Check adb status
adb connect success
step2 Create file and check status
1+0 records in
1+0 records out
104857600 bytes transferred in 0.179 secs (585796648 bytes/sec)
Create file success,file size is 100.0M ,and file path is /sdcard/tmp/test_dd
adb shell 其他命令
adb shell dd還有復制文件的功能,如下
adb shell dd if=/sdcard/DCIM/camera/timg.jpg of=/sdcard/tmp/timg_cp.jpg
#以上命令將/sdcard/DCIM/camera/timg.jpg文件復制到/sdcard/tmp/timg_cp.jpg
如果想了解adb shell 還支持哪些命令,adb shell 進入/system/bin目錄,執行ls -l即可。
由於文章長度限制,僅截取部分結果如下
lrwxr-xr-x 1 root shell 6 2009-01-01 00:00 chown -> toybox
lrwxr-xr-x 1 root shell 6 2009-01-01 00:00 chroot -> toybox
lrwxr-xr-x 1 root shell 6 2009-01-01 00:00 chrt -> toybox
lrwxr-xr-x 1 root shell 6 2009-01-01 00:00 cksum -> toybox
lrwxr-xr-x 1 root shell 6 2009-01-01 00:00 clear -> toybox
-rwxr-xr-x 1 root shell 479432 2009-01-01 00:00 climax
-rwxr-xr-x 1 root shell 65208 2009-01-01 00:00 cmd
lrwxr-xr-x 1 root shell 6 2009-01-01 00:00 cmp -> toybox
lrwxr-xr-x 1 root shell 6 2009-01-01 00:00 comm -> toybox
-rwxr-xr-x 1 root shell 207 2009-01-01 00:00 content
lrwxr-xr-x 1 root shell 6 2009-01-01 00:00 cp -> toybox
-rwxr-xr-x 1 root shell 137224 2009-01-01 00:00 cp_log
lrwxr-xr-x 1 root shell 6 2009-01-01 00:00 cpio -> toybox
-rwxr-xr-x 1 root shell 102080 2009-01-01 00:00 crash_dump32
-rwxr-xr-x 1 root shell 123360 2009-01-01 00:00 crash_dump64
-rwxr-xr-x 1 root shell 410384 2009-01-01 00:00 curl
-rwxr-xr-x 1 root shell 11040 2009-01-01 00:00 custtest
lrwxr-xr-x 1 root shell 6 2009-01-01 00:00 cut -> toybox
lrwxr-xr-x 1 root shell 10 2009-01-01 00:00 dalvikvm -> dalvikvm64
-rwxr-xr-x 1 root shell 24648 2009-01-01 00:00 dalvikvm32
-rwxr-xr-x 1 root shell 19488 2009-01-01 00:00 dalvikvm64
lrwxr-xr-x 1 root shell 6 2009-01-01 00:00 date -> toybox
lrwxr-xr-x 1 root shell 7 2009-01-01 00:00 dd -> toolbox
-rwxr-xr-x 1 root shell 11184 2009-01-01 00:00 debuggerd
-rwxr-xr-x 1 root shell 141940 2009-01-01 00:00 dex2oat
-rwxr-xr-x 1 root shell 27784 2009-01-01 00:00 dexdiag
-rwxr-xr-x 1 root shell 104384 2009-01-01 00:00 dexdump
-rwxr-xr-x 1 root shell 15416 2009-01-01 00:00 dexlist
lrwxr-xr-x 1 root shell 6 2009-01-01 00:00 df -> toybox
-rwxr-xr-x 1 root shell 11152 2009-01-01 00:00 dhrystone64_bit.elf
-rwxr-xr-x 1 root shell 19664 2009-01-01 00:00 diag_command
lrwxr-xr-x 1 root shell 6 2009-01-01 00:00 diff -> toybox
lrwxr-xr-x 1 root shell 6 2009-01-01 00:00 dirname -> toybox
lrwxr-xr-x 1 root shell 6 2009-01-01 00:00 dmesg -> toybox
lrwxr-xr-x 1 root shell 6 2009-01-01 00:00 dos2unix -> toybox
-rwxr-xr-x 1 root shell 156 2009-01-01 00:00 dpm
lrwxr-xr-x 1 root shell 6 2009-01-01 00:00 du -> toybox
-rwxr-xr-x 1 root shell 40336 2009-01-01 00:00 dumpsys
-rwxr-xr-x 1 root shell 6904 2009-01-01 00:00 ebtables
lrwxr-xr-x 1 root shell 6 2009-01-01 00:00 echo -> toybox
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