Using set -e and set -x at the beginning of shell scripts introduces strict execution safety and real-time debugging capabilities into automated Linux workflows.

Why Use set -e and set -x

• set -e (Exit Immediately on Error): Forces the script to terminate instantly if any command exits with a non-zero (failure) status. This prevents cascading errors—such as running a destructive cleanup command when a prior directory-creation or download step fails.
• set -x (Print Commands / Execution Tracing): Prints each command and its evaluated arguments to stderr prior to execution. This offers full transparency into script runtime, showing exact variable expansions and control flow.

How to Check Flag Status Within a Script

To check if these options are currently active inside a running script, inspect the $- special variable (which holds active shell flag options) or evaluate the option status using [[ $- =~ ... ]].

Method 1: Inspect Active Shell Flags via $-

Print all active option flags directly to output:

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#!/bin/bash
set -e
set -x

# Print active flags (e.g., outputs "himBHs" or flags containing 'e' and 'x')
echo "Active shell flags: $-"

Method 2: Programmatic Check Inside Script

Check flags conditionally and display clean output:

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#!/bin/bash
set -e
set -x

# Check if 'e' option is enabled
if [[ $- == *e* ]]; then
    echo "set -e is ENABLED"
else
    echo "set -e is DISABLED"
fi

# Check if 'x' option is enabled
if [[ $- == *x* ]]; then
    echo "set -x is ENABLED"
else
    echo "set -x is DISABLED"
fi

Method 3: Use Shell Built-in shopt / set -o

Inspect flag states using set -o:

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#!/bin/bash
set -e
set -x

# Display status of errexit (-e) and xtrace (-x)
set -o | grep -E 'errexit|xtrace'

Example Output

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errexit         on
xtrace          on