Skip to content

Tag: strace

How to find what folder process can’t open

I have an application that is not functioning, because it can’t find or open the folder. But it does not print the folder path. How i can find out what folders it tries to open or locate? Probably folder does not exist, or has wrong permission. But to fix this i need to know what folder application is opening… Answer

Raw clone system call not working correctly

I’m trying to use the raw clone system call to avoid having to refactor the pid 0 code into a function. Linux requires stacks to by 16 bytes, additionally, libc reserves 16 bits presumably to store ptid and ctid. The code below creates an aligned stack then exits from the child. After waiting for the child cloned by libc’s wrapper

How to see system call that executed in current time by process?

Linux utility “strace” show the list of syscall that started after run of strace. How I can see syscall that run in current moment by process? before start of strace. Answer proc offers some information about what the kernel is currently doing “for” a process /proc/${pid}/syscall /proc/${pid}/stack More information:

strace -c does not show correct seconds

I have got results for strace -c on RHEL 7 and RHEL 6 for this command: and I don’t understand why the seconds column for nanosleep is equal to 0. I had expected it to be 20. Here is a full strace report: And there is a call to nanosleep in a detailed report: So seconds must be 20, not

strace -e trace=network only showing SIGCHLD?

I am using the command: strace -tt -o ${filename} -e trace=network gdb –args ${EXECUTABLE} to track which system calls occur whilst connecting to and sending messages to a peer. However, I am only receiving the following entries: Should I not see the socket calls to read() close() etc? Answer Using strace with gdb –args ${EXECUTABLE} prints syscall of gdb, instead

Interpreting STRACE output – pipes and forks

I have the following code written in C, taken from When compiling and running this code in the terminal using strace I get the following output: Can anybody explain, line by line, what is going on in the strace output? I’ve attempted to research how to interpret strace outputs but haven’t had any luck. Thanks in advance. Answer The