Strace Command SnippetsTags:
Strace is really nice command to see what system calls are being used, it’s primary used as debugging tools for linux system calls
Q: What is a “system call” ?
A: System calls are interface via which user-space program interact with system using linux kernel.
So kernel is core that manages the system and talks and knows about hardware. Application don’t directly talk to hardware, they talk to kernel via some exposed interfaces(open, exec etc.).
Q: What is kernel-space and user-space ?
A: For simple answer, you can assume kernel space where only kernel is privileged access memory or perform operation is similar is for userspace, are where user is allowed to access memory or perform operation, for longer and more accurate answer https://unix.stackexchange.com/a/368313
Below are some samples
First sample usage:
strace ls -l
To dump output to a file:
strace -o output.txt ls -l
To get count of syscall:
strace -c ls -l
To get specific syscall:
strace -e open ls -l
To get timestamp for each syscall:
strace -t ls -l