Linux size is part of GNU binutils.
This utility is very helpful for programmers to analyze the data from the executable files (or object files).
By default, this will provide the section size, total size for the given file name.
1. Default Size Output
By default the size command displays the output which has the size information in 5 different values (text, data, bss, dec and hex) as shown below.
# size /usr/bin/rsync text data bss dec hex filename 389221 18728 71640 479589 75165 /usr/bin/rsync
The above format is in Berkeley format. All of the following three commands are the exact same.
size /usr/bin/rsync size -B /usr/bin/rsync size --format=Berkeley /usr/bin/rsync
2. Default File is a.out
If you don’t specify a file name as the argument, it will use a.out as the filename as shown below.
This will look for a.out in the current directory, and calculate the size value for this object file and display the output in the Berkeley format as shown below:
# size text data bss dec hex filename 1040 484 16 1540 604 a.out
Also, if the given file is not a binary object file, it will thrown the following File format not recognized error message:
# size /root/backup_script size: /root/backup_script: File format not recognized
3. Display Output in SysV Format
The SysV format have more detailed information in the output. This will display the details of various sections and the size and address of each and every one of the section name.
# size --format=SysV /usr/bin/rsync /usr/bin/rsync : section size addr .interp 28 4194816 .note.ABI-tag 32 4194844 .note.gnu.build-id 36 4194876 .gnu.hash 68 4194912 .dynsym 4440 4194984 .dynstr 1809 4199424 .gnu.version 370 4201234 .gnu.version_r 160 4201608 ... .... .dynamic 432 6681256 .got 8 6681688 .got.plt 1416 6681696 .data 16832 6683136 .bss 71640 6699968 .gnu_debuglink 16 0 Total 479605
4. Specify Output Value Format (Dec, Oct, or Hex)
By default the size command will display the output in the decimal format (-d option). Both of the following command will produce the same output.
# size /usr/bin/rsync # size -d /usr/bin/rsync text data bss dec hex filename 389221 18728 71640 479589 75165 /usr/bin/rsync
The following will generate the output in the ocal format. Also, this will display the “oct” column instead of the “dec” column in the output.
# size -o /usr/bin/rsync text data bss oct hex filename 01370145 044450 0213730 1650545 75165 /usr/bin/rsync
You can also combine the the format (Berkley or SysV) with this octal format as shown below.
# size -Ao /usr/bin/rsync /usr/bin/rsync : section size addr .interp 034 020001000 .note.ABI-tag 040 020001034 .note.gnu.build-id 044 020001074 .gnu.hash 0104 020001140 .dynsym 010530 020001250 .. .. .dtors 020 031371220 .jcr 010 031371240 .dynamic 0660 031371250 .got 010 031372130 .got.plt 02610 031372140 .data 040700 031375000 .bss 0213730 031435700 .gnu_debuglink 020 00 Total 01650565
The following will generate the output in the Hex format. Also, this will display the “hex” column instead of the “dec” column in the output.
# size -x /usr/bin/rsync text data bss dec hex filename 0x5f065 0x4928 0x117d8 479589 75165 /usr/bin/rsync
You can also combine the the format (Berkley or SysV) with this hex format as shown below.
# size -Ao /usr/bin/rsync # size -Ax /usr/bin/rsync /usr/bin/rsync : section size addr .interp 0x1c 0x400200 .note.ABI-tag 0x20 0x40021c .note.gnu.build-id 0x24 0x40023c .gnu.hash 0x44 0x400260 .dynsym 0x1158 0x4002a8 ..
5. Use radix Option for Output Format
Instead of -d, -o and -x, you can also use –radix and specify the number for the format as shown below:
For decimal:
# size -d /usr/bin/rsync # size --radix=10 /usr/bin/rsync text data bss dec hex filename 389221 18728 71640 479589 75165 /usr/bin/rsync
For octal:
# size -o /usr/bin/rsync # size --radix=8 /usr/bin/rsync text data bss oct hex filename 01370145 044450 0213730 1650545 75165 /usr/bin/rsync
For hex:
# size -x /usr/bin/rsync # size --radix=16 /usr/bin/rsync text data bss dec hex filename 0x5f065 0x4928 0x117d8 479589 75165 /usr/bin/rsync
Only 10,8 and 16 are valid numbers. Everything else will display the “Invalid radix” erroras shown below:
# size --radix=32 /usr/bin/rsync
size: Invalid radix: 32
size: supported targets: elf64-x86-64 elf32-i386 a.out-i386-linux pei-i386
pei-x86-64 elf64-l1om elf64-little elf64-big elf32-little
elf32-big srec symbolsrec verilog tekhex binary ihex
6. Display Common Symbols Count
The common will display the total count of all common symbols in the file. In the default format (berkeley format), this is already included in the “bss” column value.
So, this option is helpful only in the SysV format (-A). As shown below, the last line that starts with *COM* shows this value.
# size -A --common /usr/bin/myprogram /usr/bin/rsync : section size addr .interp 28 4194816 .note.ABI-tag 32 4194844 .note.gnu.build-id 36 4194876 .. .. .got.plt 1416 6681696 .data 16832 6683136 .bss 71640 6699968 .gnu_debuglink 16 0 *COM* 5 6699784 Total 939605
7. Display Total in Berkely Format
Using -t option (or –totals), we can display a new line at the bottom of the output, which will display the total values of all the files listed in the output as shown below.
# size -t /usr/bin/to* text data bss dec hex filename 7932 884 24 8840 2288 /usr/bin/toe 55893 3040 12960 71893 118d5 /usr/bin/top 63825 3924 12984 80733 13b5d (TOTALS)