Response Parsing & Debugging

# Get just the status code
curl -sS -o /dev/null -w "%{http_code}" https://api.example.com/health

# Get status code AND body
response=$(curl -sS -w "\n%{http_code}" https://api.example.com/users)
body=$(echo "$response" | sed '$d')
status=$(echo "$response" | tail -1)
echo "Status: $status"
echo "Body: $body"

# Response headers only
curl -sS -I https://api.example.com/health

# Both request and response headers
curl -sS -v https://api.example.com/health 2>&1 | grep -E "^[<>]"

# Specific header value
curl -sS -I https://api.example.com/data | grep -i "content-type"

# Detailed timing breakdown
curl -sS -o /dev/null -w "\
  DNS:        %{time_namelookup}s\n\
  Connect:    %{time_connect}s\n\
  TLS:        %{time_appconnect}s\n\
  TTFB:       %{time_starttransfer}s\n\
  Total:      %{time_total}s\n\
  Status:     %{http_code}\n\
  Size:       %{size_download} bytes\n" \
  https://api.example.com/health

# Quick timing check
curl -sS -o /dev/null -w "Total: %{time_total}s, Status: %{http_code}\n" \
  https://api.example.com/health

# Pretty-print JSON response
curl -sS https://api.example.com/users | jq '.'

# Extract specific field
curl -sS https://api.example.com/users/123 | jq '.data.email'

# Extract from array
curl -sS https://api.example.com/users | jq '.data[].name'

# Filter and transform
curl -sS https://api.example.com/users | jq '.data[] | {name, email}'

# Validate field exists (exit non-zero if null)
curl -sS https://api.example.com/users/123 | jq -e '.data.id != null'

# Verbose output (request + response headers + TLS)
curl -v https://api.example.com/health 2>&1

# Trace (raw bytes)
curl --trace - https://api.example.com/health

# Trace to file
curl --trace trace.log https://api.example.com/health