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questions.json
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questions.json
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{
"1": {
"question": "Display the first 5 lines for the input file `ip.txt`",
"ip_file": [
"ip.txt"
],
"op_file": "hi there\nhow are you\n\n2 apples\n12 bananas\n",
"ref_solution": [
"head -n5 ip.txt",
"sed '5q' ip.txt"
]
},
"2": {
"question": "Display *except* the first 5 lines for the input `blocks.txt`",
"ip_file": [
"blocks.txt"
],
"op_file": "42\n1000\n%=%=\nbrown\ngreen\n%=%=\nhi\n",
"ref_solution": [
"tail -n +6 blocks.txt",
"sed '1,5d' blocks.txt"
]
},
"3": {
"question": "Extract 5th to 9th bytes from the `greeting.txt` file",
"ip_file": [
"greeting.txt"
],
"op_file": "here\n",
"ref_solution": [
"head -c9 greeting.txt | tail -c +5",
"tail -c +5 greeting.txt | head -c5"
]
},
"4": {
"question": "Display only the first 3 lines from `ip.txt` and `fruits.txt`",
"ip_file": [
"ip.txt",
"fruits.txt"
],
"op_file": "hi there\nhow are you\n\n3) cherry\n1) apple\n2) banana\n",
"ref_solution": [
"head -q -n3 ip.txt fruits.txt",
"grep -m3 -he '' ip.txt fruits.txt"
]
},
"5": {
"question": "Display lines from `code.txt` containing `fruit[0]` literally, along with line number prefix for matching lines",
"ip_file": [
"code.txt"
],
"op_file": "2:fruit[0] = 'apple'\n",
"ref_solution": [
"grep -Fn 'fruit[0]' code.txt"
]
},
"6": {
"question": "Count the number of empty lines for the input file `ip.txt`",
"ip_file": [
"ip.txt"
],
"op_file": "3\n",
"ref_solution": [
"grep -cx '' ip.txt"
]
},
"7": {
"question": "Display all lines from `purchases.txt` except those that contain `tea` or `ash`",
"ip_file": [
"purchases.txt"
],
"op_file": "coffee\ncoffee\ntoothpaste\nsoap\n",
"ref_solution": [
"grep -vE 'tea|ash' purchases.txt"
]
},
"8": {
"question": "For the input files `purchases.txt` and `code.txt`, display only whole matching lines based on the search terms (one per line) present in the `lines.txt` file. Results should be prefixed with the corresponding input filename as well as the line number",
"ip_file": [
"lines.txt",
"purchases.txt",
"code.txt"
],
"op_file": "purchases.txt:5:toothpaste\ncode.txt:1:fruit = []\n",
"ref_solution": [
"grep -Fnxf lines.txt purchases.txt code.txt"
]
},
"9": {
"question": "For the input file `sample.txt` filter lines containing `are` or `he` as whole words as well as the line that comes before such a matching line. There should be no separator between the matching groups in the output",
"ip_file": [
"sample.txt"
],
"op_file": " 3) Hi there\n 4) How are you\n13) Much ado about nothing\n14) He he he\n",
"ref_solution": [
"grep --no-group-separator -B1 -wE 'are|he' sample.txt"
]
},
"10": {
"question": "Filter lines from `ip.txt` starting with `b` or ending with `e` or ending with `es`",
"ip_file": [
"ip.txt"
],
"op_file": "hi there\n2 apples\nblue sky\nbrown earth\n",
"ref_solution": [
"grep -E '^b|es?$' ip.txt"
]
},
"11": {
"question": "Display lines from `sample.txt` that satisfy both of these conditions:\n\n* `he` matched irrespective of case\n* either `World` or `Hi` matched case sensitively",
"ip_file": [
"sample.txt"
],
"op_file": " 1) Hello World\n 3) Hi there\n",
"ref_solution": [
"grep -i 'he' sample.txt | grep -E 'World|Hi'",
"sed -nE '/he/I{/World|Hi/p}' sample.txt",
"awk 'tolower($0) ~ /he/ && /World|Hi/' sample.txt"
]
},
"12": {
"question": "Extract all whole words starting with `h` or `m` irrespective of case from `sample.txt`",
"ip_file": [
"sample.txt"
],
"op_file": "Hello\nHi\nHow\nmango\nMuch\nHe\nhe\nhe\n",
"ref_solution": [
"grep -iow '[hm]\\w*' sample.txt"
]
},
"13": {
"question": "For the input file `patterns.txt`, match lines starting with `s` and containing `e` and `t` in any order",
"ip_file": [
"patterns.txt"
],
"op_file": "sets tests\nsite cite kite bite\nsuper turtle sequoia\n",
"ref_solution": [
"grep -E '^s.*(e.*t|t.*e)' patterns.txt"
]
},
"14": {
"question": "From the input file `patterns.txt`, extract all whole lines having the same first and last word character",
"ip_file": [
"patterns.txt"
],
"op_file": "sets tests\nNot a pip DOWN\ny\n1 dentist 1\n_42_\n",
"ref_solution": [
"grep -xE '(\\w)(.*\\1)?' patterns.txt",
"grep -xE '\\w|(\\w).*\\1' patterns.txt"
]
},
"15": {
"question": "From the input file `patterns.txt`, extract from `-` till the end of the line, provided the characters after the hyphen are all word characters only",
"ip_file": [
"patterns.txt"
],
"op_file": "-handy\n-icy\n",
"ref_solution": [
"grep -o '\\-\\w*$' patterns.txt",
"grep -o -- '-\\w*$' patterns.txt"
]
},
"16": {
"question": "Search recursively and list the names of files containing `blue`, but do not search within the `text` directory. Hidden files should also be searched and assume that there are no links",
"ip_file": [],
"op_file": ".hidden\ncolors.txt\ntwos.txt\nbackups/color list.txt\ntable.txt\nduplicates.txt\nip.txt\n",
"ref_solution": [
"grep -rl --exclude-dir='text' 'blue'"
]
},
"17": {
"question": "Search for files containing `red` or `ello` recursively, but do not list the file if it also contains `greeting` or `earth`. Hidden files should also be searched and assume that there are no links",
"ip_file": [],
"op_file": "books.txt\nsample.txt\nbackups/color list.txt\ntable.txt\nmulti_empty_lines.txt\nduplicates.txt\n",
"ref_solution": [
"grep -rlEZ 'red|ello' | xargs -r0 grep -LE 'greeting|earth'",
"grep -rLEZ 'greeting|earth' | xargs -r0 grep -lE 'red|ello'"
]
},
"18": {
"question": "Display the number of words present in `ip.txt`",
"ip_file": [
"ip.txt"
],
"op_file": "15\n",
"ref_solution": [
"wc -w <ip.txt"
]
},
"19": {
"question": "Print the maximum display width for the input file `sample.txt`",
"ip_file": [
"sample.txt"
],
"op_file": "26\n",
"ref_solution": [
"wc -L <sample.txt"
]
},
"20": {
"question": "Sort the contents of `nums_1.txt` numerically",
"ip_file": [
"nums_1.txt"
],
"op_file": "-1\n2\n3\n20\n42\n",
"ref_solution": [
"sort -n nums_1.txt"
]
},
"21": {
"question": "Sort the contents of `nums_2.txt` according to general numerical value",
"ip_file": [
"nums_2.txt"
],
"op_file": "-1.53\n42.1e-2\n100\n+120\n3.14e+4\n123456789\n",
"ref_solution": [
"sort -g nums_2.txt"
]
},
"22": {
"question": "Sort contents of `file_size.txt` based on human readable numbers. Display the results in descending order",
"ip_file": [
"file_size.txt"
],
"op_file": "1.4G\tgames\n316M projects\n746K report.log\n104K power.log\n20K sample.txt\n",
"ref_solution": [
"sort -hr file_size.txt"
]
},
"23": {
"question": "Sort contents of `timings.txt` based on natural (version) numbers within the text",
"ip_file": [
"timings.txt"
],
"op_file": "3m20.058s\n3m42.833s\n4m3.083s\n4m11.130s\n5m35.363s\n",
"ref_solution": [
"sort -V timings.txt"
]
},
"24": {
"question": "Sort the `scores.csv` file numerically in ascending order using the contents of the second field. Header line should be preserved as the first line in the output",
"ip_file": [
"scores.csv"
],
"op_file": "Name,Maths,Physics,Chemistry\nLin,78,83,80\nCy,97,98,95\nIth,100,100,100\n",
"ref_solution": [
"(sed -u '1q' ; sort -t, -k2,2n) < scores.csv"
]
},
"25": {
"question": "Sort the contents of `duplicates.txt` by the 4th column numbers in descending order. Retain only the first copy of lines with the same number",
"ip_file": [
"duplicates.txt"
],
"op_file": "dark red,sky,rose,555\nblue,ruby,water,333\ndark red,ruby,rose,111\nbrown,toy,bread,42\n",
"ref_solution": [
"sort -t, -k4,4nr -u duplicates.txt"
]
},
"26": {
"question": "Display lines from `purchases.txt` that occur more than once",
"ip_file": [
"purchases.txt"
],
"op_file": "coffee\ntea\n",
"ref_solution": [
"sort purchases.txt | uniq -d"
]
},
"27": {
"question": "Filter the 3rd column from `duplicates.txt` and display all occurrences of duplicate items",
"ip_file": [
"duplicates.txt"
],
"op_file": "bread\nbread\nrose\nrose\nrose\n",
"ref_solution": [
"cut -d, -f3 duplicates.txt | sort | uniq -D"
]
},
"28": {
"question": "For the input file `fruits.txt` retain only unique entries based on the first two characters. For example, `abcd` and `ab12` should be considered as duplicates and neither of them will be part of the output",
"ip_file": [
"fruits.txt"
],
"op_file": "2) banana\n4) pineapple\n5) pear\n6) fig\n",
"ref_solution": [
"sort fruits.txt | uniq -u -w2"
]
},
"29": {
"question": "Count the number of times input lines are repeated in `colors.txt` and display the results as shown in the expected output panel",
"ip_file": [
"colors.txt"
],
"op_file": " 1 green\n 2 blue\n 4 brown\n",
"ref_solution": [
"sort colors.txt | uniq -c | sort -n"
]
},
"30": {
"question": "For the input file `duplicates.txt` change spaces to `-` and `,` to spaces. Display all the duplicate entries based on the 4th column (assume that the input only has 4 columns)",
"ip_file": [
"duplicates.txt"
],
"op_file": "dark-red ruby rose 111\nwhite sky bread 111\nblue ruby water 333\nlight-red purse rose 333\nyellow toy flower 333\n",
"ref_solution": [
"<duplicates.txt tr ' ,' '- ' | sort -k4,4 | uniq -f3 -D"
]
},
"31": {
"question": "Display lines present in `c1.txt` but not in `c2.txt`. Assume that the input files are already sorted",
"ip_file": [
"c1.txt",
"c2.txt"
],
"op_file": "Brown\nPurple\nTeal\n",
"ref_solution": [
"comm -23 c1.txt c2.txt",
"awk 'NR==FNR{a[$0]; next} !($0 in a)' c2.txt c1.txt",
"grep -vFxf c2.txt c1.txt"
]
},
"32": {
"question": "Combine common lines from `shopping_jan.txt` and `shopping_feb.txt` based on the first field as the key. Assume that the input files are already sorted",
"ip_file": [
"shopping_jan.txt",
"shopping_feb.txt"
],
"op_file": "banana 20 15\nsoap 3 1\n",
"ref_solution": [
"join shopping_jan.txt shopping_feb.txt"
]
},
"33": {
"question": "Join `marks_1.csv` and `marks_2.csv` based on the first field as the key. Assume that the input files are already sorted except for the header lines. The output field order should be the common 1st field, followed by the 2nd field from the second file, 2nd field from the first file and then the 4th field from the second file",
"ip_file": [
"marks_1.csv",
"marks_2.csv"
],
"op_file": "Name,Maths,Biology,Chemistry\nIth,100,100,100\nLin,78,92,80\n",
"ref_solution": [
"join -t, --header -o 1.1,2.2,1.2,2.4 marks_1.csv marks_2.csv",
"awk -F, -v OFS=, 'NR==FNR{a[$1]=$2; next} $1 in a{print $1, $2, a[$1], $4}' marks_1.csv marks_2.csv"
]
},
"34": {
"question": "Delete the second field for the input `varying_fields.csv`",
"ip_file": [
"varying_fields.csv"
],
"op_file": "apple,cherry,fig\n2,4,5,6,7,8\ndragon,centaur,mermaid\n",
"ref_solution": [
"cut -d, --complement -f2 varying_fields.csv",
"cut -d, -f1,3- varying_fields.csv"
]
},
"35": {
"question": "Delete the first three characters from each line for the input `fruits.txt`",
"ip_file": [
"fruits.txt"
],
"op_file": "cherry\napple\nbanana\nalmond\napricot\nfig\npineapple\nmango\npear\n",
"ref_solution": [
"cut -c4- fruits.txt"
]
},
"36": {
"question": "Filter 1st and 3rd fields of `varying_fields.csv` and align the output fields using space characters",
"ip_file": [
"varying_fields.csv"
],
"op_file": "apple cherry\n2 4\ndragon centaur\n",
"ref_solution": [
"cut -d, -f1,3 varying_fields.csv | column -ts,"
]
},
"37": {
"question": "Display the first 3 characters of each line separated by a `:` character from the input file `table.txt`. Assume that the input lines will have at least 3 characters",
"ip_file": [
"table.txt"
],
"op_file": "b:r:o\nb:l:u\ny:e:l\n",
"ref_solution": [
"cut -c1,2,3 --output-delimiter=: table.txt",
"sed -E 's/^(.)(.)(.).*/\\1:\\2:\\3/' table.txt",
"awk -v FS= -v OFS=: '{print $1, $2, $3}' table.txt"
]
},
"38": {
"question": "Delete other than alphabets, digits and whitespace characters from `blocks.txt`",
"ip_file": [
"blocks.txt"
],
"op_file": "\napple\nbanana\n\n314\n42\n1000\n\nbrown\ngreen\n\nhi\n",
"ref_solution": [
"tr -dc '[:alnum:][:space:]' <blocks.txt"
]
},
"39": {
"question": "The `books.txt` file has items separated by one or more `:` characters. Change this separator to a single newline character",
"ip_file": [
"books.txt"
],
"op_file": "Cradle\nMage Errant\nPiranesi\nMother of Learning\nEight\nAscendant\nMark of the Fool\nSuper Powereds\n",
"ref_solution": [
"<books.txt tr -s ':' '\\n'",
"sed -E 's/:+/\\n/g' books.txt"
]
},
"40": {
"question": "Display lines from `c1.txt` and `c2.txt` side-by-side, using a tab character as the separator",
"ip_file": [
"c1.txt",
"c2.txt"
],
"op_file": "Blue\tBlack\nBrown\tBlue\nOrange\tGreen\nPurple\tOrange\nRed\tPink\nTeal\tRed\nWhite\tWhite\n",
"ref_solution": [
"paste c1.txt c2.txt"
]
},
"41": {
"question": "Interleave the contents of `table.txt` and `books.txt` as shown below",
"ip_file": [
"table.txt",
"books.txt"
],
"op_file": "brown bread mat hair 42\nCradle:::Mage Errant:Piranesi\nblue cake mug shirt -7\nMother of Learning::Eight::::Ascendant\nyellow banana window shoes 3.14\nMark of the Fool:::Super Powereds\n",
"ref_solution": [
"paste -d'\\n' table.txt books.txt",
"sed 'R books.txt' table.txt"
]
},
"42": {
"question": "Display second column from `varying_fields.csv` as a single row",
"ip_file": [
"varying_fields.csv"
],
"op_file": "banana,3,unicorn\n",
"ref_solution": [
"cut -d, -f2 varying_fields.csv | paste -sd,"
]
},
"43": {
"question": "Combine every two lines of `purchases.txt` using comma as the separator",
"ip_file": [
"purchases.txt"
],
"op_file": "coffee,tea\nwashing powder,coffee\ntoothpaste,tea\nsoap,tea\n",
"ref_solution": [
"pr -2ats, purchases.txt"
]
},
"44": {
"question": "Divide the contents of `blocks.txt` into two equal parts (based on number of lines) and then join these parts vertically using comma as the separator",
"ip_file": [
"blocks.txt"
],
"op_file": "%=%=,1000\napple,%=%=\nbanana,brown\n%=%=,green\n3.14,%=%=\n42,hi\n",
"ref_solution": [
"pr -2ts, blocks.txt"
]
},
"45": {
"question": "Display lines from `c1.txt` and `c2.txt` side-by-side. The separator is a space character, followed by ` : ` and then another space",
"ip_file": [
"c1.txt",
"c2.txt"
],
"op_file": "Blue : Black\nBrown : Blue\nOrange : Green\nPurple : Orange\nRed : Pink\nTeal : Red\nWhite : White\n",
"ref_solution": [
"pr -mts' : ' c1.txt c2.txt"
]
},
"46": {
"question": "Retain only the last 3 characters of each line from `purchases.txt`",
"ip_file": [
"purchases.txt"
],
"op_file": "fee\ntea\nder\nfee\nste\ntea\noap\ntea\n",
"ref_solution": [
"grep -o '...$' purchases.txt",
"rev purchases.txt | cut -c-3 | rev"
]
},
"47": {
"question": "Reshape contents of `varying_fields.csv` such that 3 fields are displayed per line, separated by tab",
"ip_file": [
"varying_fields.csv"
],
"op_file": "apple\tbanana\tcherry\nfig\t2\t3\n4\t5\t6\n7\t8\tdragon\nunicorn\tcentaur\tmermaid\n",
"ref_solution": [
"<varying_fields.csv tr ',' '\\n' | pr -3ats"
]
},
"48": {
"question": "Transpose comma delimited data from `scores.csv`",
"ip_file": [
"scores.csv"
],
"op_file": "Name,Ith,Cy,Lin\nMaths,100,97,78\nPhysics,100,98,83\nChemistry,100,95,80\n",
"ref_solution": [
"tr ',' '\\n' <scores.csv | pr -$(wc -l <scores.csv)ts,",
"datamash -t, transpose <scores.csv"
]
},
"49": {
"question": "For the input file `table.txt`, split lines more than 10 characters long as shown below. An output line can still be longer than 10 characters to avoid splitting a word",
"ip_file": [
"table.txt"
],
"op_file": "brown\nbread mat\nhair 42\nblue cake\nmug shirt\n-7 yellow\nbanana\nwindow\nshoes\n3.14\n",
"ref_solution": [
"fmt -w10 table.txt"
]
},
"50": {
"question": "For the input file `blocks.txt`, number the lines that start with `%=%=` in the format as shown below",
"ip_file": [
"blocks.txt"
],
"op_file": "1) %=%=\n apple\n banana\n2) %=%=\n 3.14\n 42\n 1000\n3) %=%=\n brown\n green\n4) %=%=\n hi\n",
"ref_solution": [
"nl -w1 -s') ' -bp'^%=%=' blocks.txt",
"awk '{printf /^%=%=/ ? ++c \") \" : \" \"} 1' blocks.txt"
]
},
"51": {
"question": "For the input file `purchases.txt` replace all occurrences of `tea` with `cake` and `coffee` with `toffee`",
"ip_file": [
"purchases.txt"
],
"op_file": "toffee\ncake\nwashing powder\ntoffee\ntoothpaste\ncake\nsoap\ncake\n",
"ref_solution": [
"sed 's/tea/cake/g; s/coffee/toffee/g' purchases.txt"
]
},
"52": {
"question": "Display contents of `ip.txt` *except* for line numbers 4, 5, 6 and 7",
"ip_file": [
"ip.txt"
],
"op_file": "hi there\nhow are you\n\nblue sky\nyellow sun\nbrown earth\n",
"ref_solution": [
"sed '4,7d' ip.txt",
"head -n3 ip.txt ; tail -n +8 ip.txt"
]
},
"53": {
"question": "For the input file `sample.txt` display all lines from the start of the file till the first occurrence of `do`",
"ip_file": [
"sample.txt"
],
"op_file": " 1) Hello World\n 2) \n 3) Hi there\n 4) How are you\n 5) \n 6) Just do-it\n",
"ref_solution": [
"sed '/do/q' sample.txt",
"awk '1; /do/{exit}' sample.txt"
]
},
"54": {
"question": "Delete all groups of lines from a line containing `start` to a line containing `end` for the input file `range.txt`",
"ip_file": [
"range.txt"
],
"op_file": "mango\nicecream\nhow are you\nhave a nice day\npar,far,mar,tar\n",
"ref_solution": [
"sed '/start/,/end/d' range.txt",
"awk '/start/{f=1} !f; /end/{f=0}' range.txt"
]
},
"55": {
"question": "For the input file `anchors.txt` convert markdown anchors to hyperlinks as shown in the excepted output panel",
"ip_file": [
"anchors.txt"
],
"op_file": "[Reg Exp](#reg-exp)\n[Sub calls](#sub-calls)\n[dot meta x](#dot-meta-x)\n",
"ref_solution": [
"sed -E 's|[^\"]+\"([^\"]+)\"></a>(.+)|[\\2](#\\1)|' anchors.txt"
]
},
"56": {
"question": "For the input file `greeting.txt` surround all lowercase vowels with `[]` except for the first two vowels in the line",
"ip_file": [
"greeting.txt"
],
"op_file": "Hi ther[e]\nHave [a] n[i]c[e] d[a]y\n",
"ref_solution": [
"sed 's/[aeiou]/[&]/3g' greeting.txt"
]
},
"57": {
"question": "Display only the fourth line from `ip.txt`, `sample.txt` and `purchases.txt`",
"ip_file": [
"ip.txt",
"sample.txt",
"purchases.txt"
],
"op_file": "2 apples\n 4) How are you\ncoffee\n",
"ref_solution": [
"sed -ns '4p' ip.txt sample.txt purchases.txt",
"awk 'FNR==4{print; nextfile}' ip.txt sample.txt purchases.txt"
]
},
"58": {
"question": "For the input file `hex.txt`, use content from `replace.txt` to perform search and replace operations. Each line in `replace.txt` starts with the search term, followed by a space and then followed by the replacement term. Match the search terms only as whole words and assume that these terms do not contain any regex metacharacters",
"ip_file": [
"replace.txt",
"hex.txt"
],
"op_file": "start: 0x5000, func1: 0x5000\nend: 0x7000, func2: 0x6000\nrestart: 0xA010, func3: 0x8000\n",
"ref_solution": [
"sed -E 's|(.+) (.+)|s/\\\\b\\1\\\\b/\\2/g|' replace.txt | sed -f- hex.txt"
]
},
"59": {
"question": "Insert contents of `greeting.txt` after every line containing `coffee` for the `purchases.txt` file",
"ip_file": [
"greeting.txt",
"purchases.txt"
],
"op_file": "coffee\nHi there\nHave a nice day\ntea\nwashing powder\ncoffee\nHi there\nHave a nice day\ntoothpaste\ntea\nsoap\ntea\n",
"ref_solution": [
"sed '/coffee/r greeting.txt' purchases.txt"
]
},
"60": {
"question": "Replace every line containing `coffee` from the `purchases.txt` file with contents of `greeting.txt`",
"ip_file": [
"greeting.txt",
"purchases.txt"
],
"op_file": "Hi there\nHave a nice day\ntea\nwashing powder\nHi there\nHave a nice day\ntoothpaste\ntea\nsoap\ntea\n",
"ref_solution": [
"sed -e '/coffee/r greeting.txt' -e '//d' purchases.txt"
]
},
"61": {
"question": "The `blocks.txt` file uses `%=%=` to separate group of lines. Display the last such group",
"ip_file": [
"blocks.txt"
],
"op_file": "%=%=\nhi\n",
"ref_solution": [
"tac blocks.txt | sed '/%=%=/q' | tac"
]
},
"62": {
"question": "The `blocks.txt` file uses `%=%=` to separate group of lines. Display the last two groups",
"ip_file": [
"blocks.txt"
],
"op_file": "%=%=\nbrown\ngreen\n%=%=\nhi\n",
"ref_solution": [
"tac -bs '%=%=' blocks.txt | awk '/%=%=/ && ++c==3{exit} 1' | tac -bs '%=%='",
"awk -v n=$(grep -c '%=%=' blocks.txt) '/%=%=/ && c++==(n-2){f=1} f' blocks.txt"
]
},
"63": {
"question": "For the input file `table.txt` calculate and display the product of numbers in the last field of each line",
"ip_file": [
"table.txt"
],
"op_file": "-923.16\n",
"ref_solution": [
"awk 'BEGIN{p = 1} {p *= $NF} END{print p}' table.txt"
]
},
"64": {
"question": "Reverse contents of `blocks.txt` considering `%=%=` as the separator",
"ip_file": [
"blocks.txt"
],
"op_file": "%=%=\nhi\n%=%=\nbrown\ngreen\n%=%=\n3.14\n42\n1000\n%=%=\napple\nbanana\n",
"ref_solution": [
"tac -bs '%=%=' blocks.txt"
]
},
"65": {
"question": "Display all lines from `sample.txt` that contain `do` but not `it`",
"ip_file": [
"sample.txt"
],
"op_file": "13) Much ado about nothing\n",
"ref_solution": [
"awk '/do/ && !/it/' sample.txt",
"sed -n '/do/{/it/!p}' sample.txt",
"grep 'do' sample.txt | grep -v 'it'",
"grep -P '^(?!.*it).*do' sample.txt"
]
},
"66": {
"question": "Extract the contents between `()` or `)(` from each line of `fun.txt`. Assume that the `()` characters will be present only once every line",
"ip_file": [
"fun.txt"
],
"op_file": "ice\nalmond\nyoyo\n",
"ref_solution": [
"awk -F'[()]' '{print $2}' fun.txt",
"grep -oP '[()]\\K[^()]+(?=[()])' fun.txt"
]
},
"67": {
"question": "For the input file `ip.txt` filter paragraphs *not* containing digit characters. Use an empty line to separate the matching paragraphs",
"ip_file": [
"ip.txt"
],
"op_file": "hi there\nhow are you\n\nblue sky\nyellow sun\nbrown earth\n",
"ref_solution": [
"awk -v RS= '!/[0-9]/{print s $0; s=\"\\n\"}' ip.txt"
]
},
"68": {
"question": "For the input file `varying_fields.csv` display 3rd field followed by the 1st field. Use `:` as the output field separator",
"ip_file": [
"varying_fields.csv"
],
"op_file": "cherry:apple\n4:2\ncentaur:dragon\n",
"ref_solution": [
"awk -F, '{print $3 \":\" $1}' varying_fields.csv",
"awk -F, '{print $3, $1}' OFS=: varying_fields.csv"
]
},
"69": {
"question": "For the input file `ip.txt` filter lines containing 3 or more lowercase vowels",
"ip_file": [
"ip.txt"
],
"op_file": "hi there\nhow are you\n12 bananas\nyellow sun\nbrown earth\n",
"ref_solution": [
"awk -F'[aeiou]' 'NF>3' ip.txt",
"grep -E '([aeiou].*){3}' ip.txt"
]
},
"70": {
"question": "From `blocks.txt` extract only the 3rd block. A line containing `%=%=` determines the start of a block",
"ip_file": [
"blocks.txt"
],
"op_file": "%=%=\nbrown\ngreen\n",
"ref_solution": [
"awk '$0 == \"%=%=\"{c++} c==3' blocks.txt"
]
},
"71": {
"question": "Squeeze consecutive empty lines in the `multi_empty_lines.txt` input file to a single empty line. Construct a solution assuming that there are no empty lines at the start/end of the input file",
"ip_file": [
"multi_empty_lines.txt"
],
"op_file": "hello\n\nworld\n\napple\nbanana\ncherry\n\ntea coffee\nchocolate\n",
"ref_solution": [
"cat -s multi_empty_lines.txt",
"awk -v RS= '{print s $0; s=\"\\n\"}' multi_empty_lines.txt",
"grep --group-separator= -A0 '.' multi_empty_lines.txt"
]
},
"72": {
"question": "Retain only the first copy of repeated lines from the `duplicates.txt` input file. Use only the contents of the last field for determining duplicates and the order of the qualifying lines should be the same as the input order",
"ip_file": [
"duplicates.txt"
],
"op_file": "brown,toy,bread,42\ndark red,ruby,rose,111\nblue,ruby,water,333\ndark red,sky,rose,555\n",
"ref_solution": [
"awk -F, '!seen[$NF]++' duplicates.txt"
]
},
"73": {
"question": "For the input file `scores.csv`, add another column named `GP` which is calculated out of 100 by giving 50% weightage to `Maths` and 25% each for `Physics` and `Chemistry`",
"ip_file": [
"scores.csv"
],
"op_file": "Name,Maths,Physics,Chemistry,GP\nIth,100,100,100,100\nCy,97,98,95,96.75\nLin,78,83,80,79.75\n",
"ref_solution": [
"awk -F, -v OFS=, '{$(NF+1) = NR==1 ? \"GP\" : ($2/2 + ($3+$4)/4)} 1' scores.csv"
]
},
"74": {
"question": "For the input file `sample.txt`, print a matching line containing `do` only if `you` is found two lines before. For example, if `do` is found on line number 10 and the 8th line contains `you`, then the 10th line should be printed",
"ip_file": [
"sample.txt"
],
"op_file": " 6) Just do-it\n",
"ref_solution": [
"awk 'p2 ~ /you/ && /do/; {p2=p1; p1=$0}' sample.txt"
]
},
"75": {
"question": "Display lines from `scores.csv` by matching the first field based on a list of names from the `names.txt` file",
"ip_file": [
"names.txt",
"scores.csv"
],
"op_file": "Ith,100,100,100\nLin,78,83,80\n",
"ref_solution": [
"awk -F, 'NR==FNR{a[$1]; next} $1 in a' names.txt scores.csv"
]
},
"76": {
"question": "For the input file `twos.txt`, display only the unique lines. Assume each line has exactly two fields separated by a space character. Compare the lines irrespective of order of the fields. For example, `hehe haha` and `haha hehe` will be considered as duplicates, and thus neither of them will qualify as unique",
"ip_file": [
"twos.txt"
],
"op_file": "true blue\nhehe bebe\ntru eblue\n",
"ref_solution": [
"awk 'NR==FNR{c[$1,$2]++; next} (c[$1,$2] + c[$2,$1]) == 1' twos.txt twos.txt"
]
},
"77": {
"question": "For the input file `table.txt`, change contents of the 3rd field to all uppercase",
"ip_file": [
"table.txt"
],
"op_file": "brown bread MAT hair 42\nblue cake MUG shirt -7\nyellow banana WINDOW shoes 3.14\n",
"ref_solution": [
"awk '{$3 = toupper($3)} 1' table.txt",
"sed 's/[^ ]*/\\U&/3' table.txt"
]
}
}