SiginfoBasic

SiginfoBasic is the most basic class for SigInfo. It prints the current call stack to its output

SiginfoBasic class

class siginfo.siginfoclass.SiginfoBasic(info=True, usr1=True, usr2=False, output=None)

Base class for the SigInfo module

Parameters:

• info (bool) – Listen for SIGINFO Default: True (works only on Mac and BSD)

• usr1 (bool) – Listen for SIGUSR1 Default: True

• usr2 (bool)) – Listen for SIGUSR2 Default: True

• output (_io.TextIOWrapper) – IO interface for writing output and log. Default: sys.stdout

COLUMNS

Width of Terminal (number of columns) Default: Auto (Fallback to 80)

Type:

int

MAX_LEVELS

Number of parent stack frames to display Default: 0 (only current frame)

Type:

int

Returns:

SigInfoBasic

Return type:

An instance of the class

Example

foo = SiginfoBasic()

# Write up to 120 characters per line
foo.COLUMNS = 120

# Write three parent stack frame
foo.MAX_LEVELS = 3

# create executeable to send signal to Python script
foo.create_info_script('/usr/local/bin')

# Code of your regular Python script
def read_lines():
    a = 12
    b = 15
    i = 0
    print('Loading a very long file')
    with open('many_rows.txt') as fh:
        for line in fh:
            i += 1
            # print(line)
            time.sleep(1)
    print('Done loading')

# Some useless function so we have more stacks
def main2():
    read_lines()

def main():
    main2()

if __name__ == '__main__':
    main()

In another terminal window:

# send signal via custom script
/usr/local/bin/siginfo-USR1

# Output:
========================================================================================================================
LEVEL       0
METHOD      read_lines
LINE NUMBER:    33
------------------------------------------------------------------------------------------------------------------------
LOCALS
VARIABLE | TYPE            | VALUE
i        | int             | 1
fh       | TextIOWrapper   | <_io.TextIOWrapper name='many_rows.txt' mode='r' encoding='UTF-8'>
b        | int             | 15
a        | int             | 12
line     | str             | Row 1

------------------------------------------------------------------------------------------------------------------------
SCOPE   <code object read_lines at 0x108c30c90, file "long_script.py", line 24>
CALLER  <code object main2 at 0x108c309c0, file "long_script.py", line 21>
========================================================================================================================

========================================================================================================================
LEVEL       1
METHOD      main2
LINE NUMBER:    22
------------------------------------------------------------------------------------------------------------------------
LOCALS
VARIABLE                                               | TYPE                       | VALUE
------------------------------------------------------------------------------------------------------------------------
SCOPE   <code object main2 at 0x108c309c0, file "long_script.py", line 21>
CALLER  <code object main at 0x108c30ed0, file "long_script.py", line 18>
========================================================================================================================

...

create_info_script(path=None, prefix='', overwrite=False)

Create an executable on the file system to send the appropiate signal.

For user convenience, create executable filess in the specified path that can be used to send corresponding signals to the parent’s script.

Parameters:

• path (str) – path to executable files (default $HOME)

• prefix (str) – Prefix of the executable file name (default ‘’)

• overwrite (bool) – Overwrite existing executables (default False)

Return type:

None