Difference between revisions of "Strace"

From Freephile Wiki
Jump to navigation Jump to search
m (Text replacement - "<abbr title="[^"]+">(.*)<\/abbr>" to "$1")
 
(2 intermediate revisions by the same user not shown)
Line 1: Line 1:
 
System Trace is a tool for hackers.
 
System Trace is a tool for hackers.
  
Say you have some python application such as [[Reposurgeon]] that you need to understand better.  You can attach <code>strace</code> to the <code><abbrev title="process id">pid</abbrev></code> of the running application to see the underlying system calls being made.
+
Say you have some python application such as [[Reposurgeon]] that you need to understand better.  You can attach <code>strace</code> to the <code>pid</code> of the running application to see the underlying system calls being made.
 
<source lang="bash">
 
<source lang="bash">
sudo strace -f -s128 -p$(ps -o lwp= -LC python2 | tail -1)
+
sudo strace -f -s128 -e trace=open -p$(ps -o lwp= -LC python2 | tail -1)
 
# -f follow child processes
 
# -f follow child processes
 
# -s string width
 
# -s string width
 
+
# -e set which calls you want to see.  Using trace=open is like sudo lsof -ad3-999 -c python2
 
</source>
 
</source>
  

Latest revision as of 02:32, 12 January 2016

System Trace is a tool for hackers.

Say you have some python application such as Reposurgeon that you need to understand better. You can attach strace to the pid of the running application to see the underlying system calls being made.

sudo strace -f -s128 -e trace=open -p$(ps -o lwp= -LC python2 | tail -1)
# -f follow child processes
# -s string width
# -e set which calls you want to see.  Using trace=open is like sudo lsof -ad3-999 -c python2


write(1, "reposurgeon: r10952 copynode filemap is <PathMap: branches/784.919Merge/diag/Makefile branches/784.919Merge/diag/changelog branc"..., 1024) = 1024
write(1, "/cmts.cmd.h branches/784.919Merge/diag/cli/commands/cmts_dsg.cmd.h branches/784.919Merge/diag/cli/commands/copy.cmd branches/784"..., 412067840) = 412067840
write(1, "c/zebos/rip/rip_distance.c trunk/linux/src/zebos/rip/rip_distance.h trunk/linux/src/zebos/rip/rip_host.h trunk/linux/src/zebos/r"..., 888) = 888
munmap(0x7f888d31c000, 412069888)       = 0
munmap(0x7f885c126000, 412069888)       = 0
mmap(NULL, 412069888, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f888d31d000
mmap(NULL, 412069888, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f8874a22000
munmap(0x7f888d31d000, 412069888)       = 0
mmap(NULL, 412073984, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f885c126000
munmap(0x7f8874a22000, 412069888)       = 0
mremap(0x7f885c126000, 412073984, 412069888, MREMAP_MAYMOVE) = 0x7f885c126000
mmap(NULL, 412073984, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f888d31c000
mremap(0x7f888d31c000, 412073984, 412069888, MREMAP_MAYMOVE) = 0x7f888d31c000
write(1, "reposurgeon: r10952 copynode filemap is <PathMap: branches/784.919Merge/diag/Makefile branches/784.919Merge/diag/changelog branc"..., 1024) = 1024
write(1, "/cmts.cmd.h branches/784.919Merge/diag/cli/commands/cmts_dsg.cmd.h branches/784.919Merge/diag/cli/commands/copy.cmd branches/784"..., 412067840) = 412067840
write(1, "c/zebos/rip/rip_distance.c trunk/linux/src/zebos/rip/rip_distance.h trunk/linux/src/zebos/rip/rip_host.h trunk/linux/src/zebos/r"..., 888) = 888
munmap(0x7f888d31c000, 412069888)       = 0
munmap(0x7f885c126000, 412069888)       = 0
mmap(NULL, 412069888, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f888d31d000
mmap(NULL, 412069888, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f8874a22000
munmap(0x7f888d31d000, 412069888)       = 0
mmap(NULL, 412073984, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f885c126000
munmap(0x7f8874a22000, 412069888)       = 0
mremap(0x7f885c126000, 412073984, 412069888, MREMAP_MAYMOVE) = 0x7f885c126000
mmap(NULL, 412073984, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f888d31c000
mremap(0x7f888d31c000, 412073984, 412069888, MREMAP_MAYMOVE) = 0x7f888d31c000
write(1, "reposurgeon: r10952 copynode filemap is <PathMap: branches/784.919Merge/diag/Makefile branches/784.919Merge/diag/changelog branc"..., 1024) = 1024
write(1, "/cmts.cmd.h branches/784.919Merge/diag/cli/commands/cmts_dsg.cmd.h branches/784.919Merge/diag/cli/commands/copy.cmd branches/784"..., 412067840) = 412067840
write(1, "c/zebos/rip/rip_distance.c trunk/linux/src/zebos/rip/rip_distance.h trunk/linux/src/zebos/rip/rip_host.h trunk/linux/src/zebos/r"..., 888) = 888
munmap(0x7f888d31c000, 412069888)       = 0
munmap(0x7f885c126000, 412069888)       = 0
mmap(NULL, 412069888, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f888d31d000
mmap(NULL, 412069888, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f8874a22000
munmap(0x7f888d31d000, 412069888)       = 0
mmap(NULL, 412073984, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f885c126000
munmap(0x7f8874a22000, 412069888)       = 0
mremap(0x7f885c126000, 412073984, 412069888, MREMAP_MAYMOVE) = 0x7f885c126000
mmap(NULL, 412073984, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f888d31c000
mremap(0x7f888d31c000, 412073984, 412069888, MREMAP_MAYMOVE) = 0x7f888d31c000
write(1, "reposurgeon: r10952 copynode filemap is <PathMap: branches/784.919Merge/diag/Makefile branches/784.919Merge/diag/changelog branc"..., 1024) = 1024
write(1, "/cmts.cmd.h branches/784.919Merge/diag/cli/commands/cmts_dsg.cmd.h branches/784.919Merge/diag/cli/commands/copy.cmd branches/784"..., 412067840) = 412067840
write(1, "c/zebos/rip/rip_distance.c trunk/linux/src/zebos/rip/rip_distance.h trunk/linux/src/zebos/rip/rip_host.h trunk/linux/src/zebos/r"..., 888) = 888
munmap(0x7f888d31c000, 412069888)       = 0
munmap(0x7f885c126000, 412069888)       = 0