LPIC-1 Shells, Scripting and Data Management Practice Question

Answer analysis

Option-by-option breakdown

For each option: why learners choose it and why it is or isn't the right answer here.

• ✓

  while IFS= read -r line; do echo "$line"; done < file.txt

  Why this is correct

  Setting IFS to an empty value prevents read from trimming leading and trailing whitespace, and the -r option disables backslash escape processing. Together they preserve the line exactly as it appears in the file, satisfying the requirement to keep whitespace and backslashes intact during iteration.

• ✗

  while read line; do echo "$line"; done < file.txt

  Why it's wrong here

  The default read behavior strips leading and trailing IFS whitespace and interprets backslashes as escape characters. This would alter lines that begin or end with spaces or contain backslashes, so it does not preserve the exact content required by the scenario.

• ✗

  while read -r line; do echo "$line"; done < file.txt

  Why it's wrong here

  The -r option correctly prevents backslash interpretation, but without clearing IFS the read builtin still strips leading and trailing IFS whitespace. Lines that begin or end with spaces or tabs would be modified, so this does not fully meet the requirement to preserve whitespace.

• ✗

  for line in $(cat file.txt); do echo "$line"; done

  Why it's wrong here

  This approach performs word splitting on the entire file contents, so lines with spaces are broken into multiple words and the loop iterates over words rather than lines. It also loses empty lines and any original line boundaries, making it unsuitable for reading a file line by line.

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