Linux pmap Command Tutorial for Beginners (5 Examples)
Linux command line offers a lot of tools that help you know more about processes that are currently active in your system. One such utility is pmap, which reports the process memory map. In this tutorial, we will discuss the basics of pmap using some easy to understand examples.
But before we do that, it’s worth mentioning all examples here have been tested on an Ubuntu 18.04 LTS machine.
Linux pmap command
The pmap command in Linux lets you see the memory map of one or more than one processes. Following is its syntax:
pmap [options] pid […]
And here’s how the tool’s man page explains it:
The pmap command reports the memory map of a process or processes.
Following are some Q&A-styled examples that should give you an even better idea on how the pmap command works.
Q1. How to use pmap?
Basic usage is simple. Just execute the ‘pmap’ command without any option. Of course, you need to pass a process PID as input.
For example, I used pmap in the following way:
pmap 5146
And here’s a part of output that was produced:
5146: gedit
000055bde4835000 8K r-x-- gedit
000055bde4a36000 4K r---- gedit
000055bde4a37000 4K rw--- gedit
000055bde5d32000 13944K rw--- [ anon ]
00007fc910000000 132K rw--- [ anon ]
00007fc910021000 65404K ----- [ anon ]
00007fc918000000 896K rw--- [ anon ]
00007fc9180e0000 64640K ----- [ anon ]
00007fc91c750000 204K r---- UbuntuMono-R.ttf
00007fc91c783000 644K r-x-- libaspell.so.15.2.0
00007fc91c824000 2048K ----- libaspell.so.15.2.0
00007fc91ca24000 20K r---- libaspell.so.15.2.0
00007fc91ca29000 4K rw--- libaspell.so.15.2.0
00007fc91ca2a000 8K r-x-- libenchant_aspell.so
00007fc91ca2c000 2044K ----- libenchant_aspell.so
00007fc91cc2b000 4K r---- libenchant_aspell.so
00007fc91cc2c000 4K rw--- libenchant_aspell.so
00007fc91cc2d000 44K r-x-- libenchant_hspell.so
00007fc91cc38000 2044K ----- libenchant_hspell.so
00007fc91ce37000 4K r---- libenchant_hspell.so
00007fc91ce38000 12K rw--- libenchant_hspell.so
00007fc91ce3b000 428K r-x-- libhunspell-1.6.so.0.0.1
00007fc91cea6000 2044K ----- libhunspell-1.6.so.0.0.1
00007fc91d0a5000 4K r---- libhunspell-1.6.so.0.0.1
00007fc91d0a6000 16K rw--- libhunspell-1.6.so.0.0.1
00007fc91d0aa000 16K r-x-- libenchant_myspell.so
00007fc91d0ae000 2048K ----- libenchant_myspell.so
00007fc91d2ae000 4K r---- libenchant_myspell.so
...
...
...
So there you go, the output first shows you the name of the process and then follows it up with the memory map.
Q2. How make pmap show extended output?
To make pmap show output in extended format, use the -x command line option. For example:
pmap -x 5146
Following is a part of the output produced:
5146: gedit
Address Kbytes RSS Dirty Mode Mapping
000055bde4835000 8 4 0 r-x-- gedit
000055bde4835000 0 0 0 r-x-- gedit
000055bde4a36000 4 4 4 r---- gedit
000055bde4a36000 0 0 0 r---- gedit
000055bde4a37000 4 4 4 rw--- gedit
000055bde4a37000 0 0 0 rw--- gedit
000055bde5d32000 13944 13692 13692 rw--- [ anon ]
000055bde5d32000 0 0 0 rw--- [ anon ]
00007fc910000000 132 44 44 rw--- [ anon ]
00007fc910000000 0 0 0 rw--- [ anon ]
00007fc910021000 65404 0 0 ----- [ anon ]
00007fc910021000 0 0 0 ----- [ anon ]
00007fc918000000 896 896 896 rw--- [ anon ]
00007fc918000000 0 0 0 rw--- [ anon ]
00007fc9180e0000 64640 0 0 ----- [ anon ]
00007fc9180e0000 0 0 0 ----- [ anon ]
00007fc91c750000 204 136 0 r---- UbuntuMono-R.ttf
00007fc91c750000 0 0 0 r---- UbuntuMono-R.ttf
00007fc91c783000 644 472 0 r-x-- libaspell.so.15.2.0
00007fc91c783000 0 0 0 r-x-- libaspell.so.15.2.0
00007fc91c824000 2048 0 0 ----- libaspell.so.15.2.0
00007fc91c824000 0 0 0 ----- libaspell.so.15.2.0
00007fc91ca24000 20 20 20 r---- libaspell.so.15.2.0
00007fc91ca24000 0 0 0 r---- libaspell.so.15.2.0
00007fc91ca29000 4 4 4 rw--- libaspell.so.15.2.0
00007fc91ca29000 0 0 0 rw--- libaspell.so.15.2.0
00007fc91ca2a000 8 8 0 r-x-- libenchant_aspell.so
00007fc91ca2a000 0 0 0 r-x-- libenchant_aspell.so
00007fc91ca2c000 2044 0 0 ----- libenchant_aspell.so
00007fc91ca2c000 0 0 0 ----- libenchant_aspell.so
00007fc91cc2b000 4 4 4 r---- libenchant_aspell.so
00007fc91cc2b000 0 0 0 r---- libenchant_aspell.so
...
...
...
Note that if you need even more details, you can use the -X command line option.
Q3. How to make pmap show device format in output?
This can be done using the -d command line option. For example:
pmap -d 5146
And here’s a part of the output produced:
5146: gedit
Address Kbytes Mode Offset Device Mapping
000055bde4835000 8 r-x-- 0000000000000000 008:00008 gedit
000055bde4a36000 4 r---- 0000000000001000 008:00008 gedit
000055bde4a37000 4 rw--- 0000000000002000 008:00008 gedit
000055bde5d32000 13944 rw--- 0000000000000000 000:00000 [ anon ]
00007fc910000000 132 rw--- 0000000000000000 000:00000 [ anon ]
00007fc910021000 65404 ----- 0000000000000000 000:00000 [ anon ]
00007fc918000000 896 rw--- 0000000000000000 000:00000 [ anon ]
00007fc9180e0000 64640 ----- 0000000000000000 000:00000 [ anon ]
00007fc91c750000 204 r---- 0000000000000000 008:00008 UbuntuMono-R.ttf
00007fc91c783000 644 r-x-- 0000000000000000 008:00008 libaspell.so.15.2.0
00007fc91c824000 2048 ----- 00000000000a1000 008:00008 libaspell.so.15.2.0
00007fc91ca24000 20 r---- 00000000000a1000 008:00008 libaspell.so.15.2.0
00007fc91ca29000 4 rw--- 00000000000a6000 008:00008 libaspell.so.15.2.0
00007fc91ca2a000 8 r-x-- 0000000000000000 008:00008 libenchant_aspell.so
00007fc91ca2c000 2044 ----- 0000000000002000 008:00008 libenchant_aspell.so
00007fc91cc2b000 4 r---- 0000000000001000 008:00008 libenchant_aspell.so
00007fc91cc2c000 4 rw--- 0000000000002000 008:00008 libenchant_aspell.so
00007fc91cc2d000 44 r-x-- 0000000000000000 008:00008 libenchant_hspell.so
00007fc91cc38000 2044 ----- 000000000000b000 008:00008 libenchant_hspell.so
00007fc91ce37000 4 r---- 000000000000a000 008:00008 libenchant_hspell.so
00007fc91ce38000 12 rw--- 000000000000b000 008:00008 libenchant_hspell.so
...
...
...
So you can see a new column ‘device’ was added in the output.
If you don’t want to see stuff like column names in the pmap output, you can use the -q command line option.
For example:
pmap -q -d 5146
Following was the output:
5146: gedit
000055bde4835000 8 r-x-- 0000000000000000 008:00008 gedit
000055bde4a36000 4 r---- 0000000000001000 008:00008 gedit
000055bde4a37000 4 rw--- 0000000000002000 008:00008 gedit
000055bde5d32000 13944 rw--- 0000000000000000 000:00000 [ anon ]
00007fc910000000 132 rw--- 0000000000000000 000:00000 [ anon ]
00007fc910021000 65404 ----- 0000000000000000 000:00000 [ anon ]
00007fc918000000 896 rw--- 0000000000000000 000:00000 [ anon ]
00007fc9180e0000 64640 ----- 0000000000000000 000:00000 [ anon ]
00007fc91c750000 204 r---- 0000000000000000 008:00008 UbuntuMono-R.ttf
00007fc91c783000 644 r-x-- 0000000000000000 008:00008 libaspell.so.15.2.0
00007fc91c824000 2048 ----- 00000000000a1000 008:00008 libaspell.so.15.2.0
00007fc91ca24000 20 r---- 00000000000a1000 008:00008 libaspell.so.15.2.0
00007fc91ca29000 4 rw--- 00000000000a6000 008:00008 libaspell.so.15.2.0
00007fc91ca2a000 8 r-x-- 0000000000000000 008:00008 libenchant_aspell.so
00007fc91ca2c000 2044 ----- 0000000000002000 008:00008 libenchant_aspell.so
00007fc91cc2b000 4 r---- 0000000000001000 008:00008 libenchant_aspell.so
00007fc91cc2c000 4 rw--- 0000000000002000 008:00008 libenchant_aspell.so
00007fc91cc2d000 44 r-x-- 0000000000000000 008:00008 libenchant_hspell.so
00007fc91cc38000 2044 ----- 000000000000b000 008:00008 libenchant_hspell.so
00007fc91ce37000 4 r---- 000000000000a000 008:00008 libenchant_hspell.so
00007fc91ce38000 12 rw--- 000000000000b000 008:00008 libenchant_hspell.so
So you can see the header was removed from the output.
Q5. How to make pmap show full paths in output?
In case you want pmap to show full path to files in the mapping column, you can use the -p command line option.
For example:
pmap -p 5146
And here’s the output produced by this command:
5146: gedit
000055bde4835000 8K r-x-- /usr/bin/gedit
000055bde4a36000 4K r---- /usr/bin/gedit
000055bde4a37000 4K rw--- /usr/bin/gedit
000055bde5d32000 13944K rw--- [ anon ]
00007fc910000000 132K rw--- [ anon ]
00007fc910021000 65404K ----- [ anon ]
00007fc918000000 896K rw--- [ anon ]
00007fc9180e0000 64640K ----- [ anon ]
00007fc91c750000 204K r---- /usr/share/fonts/truetype/ubuntu/UbuntuMono-R.ttf
00007fc91c783000 644K r-x-- /usr/lib/x86_64-linux-gnu/libaspell.so.15.2.0
00007fc91c824000 2048K ----- /usr/lib/x86_64-linux-gnu/libaspell.so.15.2.0
00007fc91ca24000 20K r---- /usr/lib/x86_64-linux-gnu/libaspell.so.15.2.0
00007fc91ca29000 4K rw--- /usr/lib/x86_64-linux-gnu/libaspell.so.15.2.0
00007fc91ca2a000 8K r-x-- /usr/lib/x86_64-linux-gnu/enchant/libenchant_aspell.so
00007fc91ca2c000 2044K ----- /usr/lib/x86_64-linux-gnu/enchant/libenchant_aspell.so
00007fc91cc2b000 4K r---- /usr/lib/x86_64-linux-gnu/enchant/libenchant_aspell.so
00007fc91cc2c000 4K rw--- /usr/lib/x86_64-linux-gnu/enchant/libenchant_aspell.so
00007fc91cc2d000 44K r-x-- /usr/lib/x86_64-linux-gnu/enchant/libenchant_hspell.so
00007fc91cc38000 2044K ----- /usr/lib/x86_64-linux-gnu/enchant/libenchant_hspell.so
00007fc91ce37000 4K r---- /usr/lib/x86_64-linux-gnu/enchant/libenchant_hspell.so
00007fc91ce38000 12K rw--- /usr/lib/x86_64-linux-gnu/enchant/libenchant_hspell.so
00007fc91ce3b000 428K r-x-- /usr/lib/x86_64-linux-gnu/libhunspell-1.6.so.0.0.1
00007fc91cea6000 2044K ----- /usr/lib/x86_64-linux-gnu/libhunspell-1.6.so.0.0.1
00007fc91d0a5000 4K r---- /usr/lib/x86_64-linux-gnu/libhunspell-1.6.so.0.0.1
00007fc91d0a6000 16K rw--- /usr/lib/x86_64-linux-gnu/libhunspell-1.6.so.0.0.1
00007fc91d0aa000 16K r-x-- /usr/lib/x86_64-linux-gnu/enchant/libenchant_myspell.so
00007fc91d0ae000 2048K ----- /usr/lib/x86_64-linux-gnu/enchant/libenchant_myspell.so
00007fc91d2ae000 4K r---- /usr/lib/x86_64-linux-gnu/enchant/libenchant_myspell.so
00007fc91d2af000 4K rw--- /usr/lib/x86_64-linux-gnu/enchant/libenchant_myspell.so
00007fc91d2b0000 44K r-x-- /usr/lib/x86_64-linux-gnu/enchant/libenchant_ispell.so
00007fc91d2bb000 2048K ----- /usr/lib/x86_64-linux-gnu/enchant/libenchant_ispell.so
So you can see that file names with complete paths are produced in output.
Conclusion
If your work involves dealing with process memory maps, this tool is for you. In this tutorial, we have described the basic usage of this command. Once you’re done practicing what all we’ve discussed here, head to the tool’s man page to learn more about it.
About Himanshu Arora
Himanshu Arora has been working on Linux since 2007. He carries professional experience in system level programming, networking protocols, and command line. In addition to HowtoForge, Himanshu’s work has also been featured in some of world’s other leading publications including Computerworld, IBM DeveloperWorks, and Linux Journal.
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