Regular Expressions 101

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An explanation of your regex will be automatically generated as you type.
Detailed match information will be displayed here automatically.
  • All Tokens
  • Common Tokens
  • General Tokens
  • Anchors
  • Meta Sequences
  • Quantifiers
  • Group Constructs
  • Character Classes
  • Flags/Modifiers
  • Substitution
  • A single character of: a, b or c
    [abc]
  • A character except: a, b or c
    [^abc]
  • A character in the range: a-z
    [a-z]
  • A character not in the range: a-z
    [^a-z]
  • A character in the range: a-z or A-Z
    [a-zA-Z]
  • Any single character
    .
  • Alternate - match either a or b
    a|b
  • Any whitespace character
    \s
  • Any non-whitespace character
    \S
  • Any digit
    \d
  • Any non-digit
    \D
  • Any word character
    \w
  • Any non-word character
    \W
  • Non-capturing group
    (?:...)
  • Capturing group
    (...)
  • Zero or one of a
    a?
  • Zero or more of a
    a*
  • One or more of a
    a+
  • Exactly 3 of a
    a{3}
  • 3 or more of a
    a{3,}
  • Between 3 and 6 of a
    a{3,6}
  • Start of string
    ^
  • End of string
    $
  • A word boundary
    \b
  • Non-word boundary
    \B

Regular Expression
No Match

r"
"
gm

Test String

Code Generator

Language

Generated Code

// include the latest version of the regex crate in your Cargo.toml extern crate regex; use regex::Regex; fn main() { let regex = Regex::new(r"(?m)Column ([0-9]+): (.*)").unwrap(); let string = "File name: Pandora101s1_Izana_L2Tot_rnvs1p1-7.txt File generation date: 20200602T091315Z Data description: Level 2 total columns file Data file version: rnvs1p1-7 Data product status: Nitrogen dioxide data are official Local principal investigator: Alberto Redondas Network principal investigator: Alexander Cede Instrument type: Pandora Instrument number: 101 Spectrometer number: 1 Processing software version used: BlickP v1.7.16 Full location name: Izana Atmospheric Research Center Short location name: Izana Country of location: Spain Location latitude [deg]: 28.3090 Location longitude [deg]: -16.4994 Location altitude [m]: 2360 Data start time: 20181126T101552Z Data end time: 20200601T195357Z Data caveats: None --------------------------------------------------------------------------------------- Column 1: UT date and time for center of measurement, yyyymmddThhmmssZ (ISO 8601) Column 2: Fractional days since 1-Jan-2000 UT midnight for center of measurement Column 3: Effective duration of measurement in seconds Column 4: Solar zenith angle for center of measurement in degree Column 5: Solar azimuth for center of measurement in degree, 0=north, increases clockwise Column 6: Lunar zenith angle for center of measurement in degree Column 7: Lunar azimuth for center of measurement in degree, 0=north, increases clockwise Column 8: Nitrogen dioxide total vertical column amount [Dobson Units], -9e99=retrieval not successful Column 9: Uncertainty of nitrogen dioxide total vertical column amount [Dobson Units] based on measured uncertainty, -8=retrieval not successful, -1=cross section is zero in this wavelength range, -3=spectral fitting was done, but no uncertainty could be retrieved Column 10: Direct nitrogen dioxide air mass factor Column 11: Diffuse correction applied before fitting at effective fitting wavelength for nitrogen dioxide [%], 0=no diffuse correction applied or fitting not successful, >0=measured diffuse correction, <0=(negative value of) calculated diffuse correction Column 12: L2 data quality flag for nitrogen dioxide: 0=assured high quality, 1=assured medium quality, 2=assured low quality, 10=not-assured high quality, 11=not-assured medium quality, 12=not-assured low quality, 20=unusable high quality, 21=unusable medium quality, 22=unusable low quality Column 13: Sum over 2^i using those i, for which the corresponding L2 data quality parameter for nitrogen dioxide exceeds the DQ1 limit, 0=L2Fit data quality above 0, 1=Uncertainty too high, 2=Signal to noise ratio too low, 3=Air mass factor too large Column 14: Sum over 2^i using those i, for which the corresponding L2 data quality parameter for nitrogen dioxide exceeds the DQ2 limit (same parameters as for DQ1) Column 15: Fitting result index: 0,1,2=no error or warning, 3,4=warning, >4=error Column 16: Normalized rms of spectral fitting residuals weighted with measured uncertainty, -9=fitting not successful or no uncertainty given Column 17: Expected normalized rms of weighted spectral fitting residuals based on measured uncertainty, -9=fitting not successful or no uncertainty given Column 18: Expected normalized rms of weighted spectral fitting residuals based on instrumental uncertainty, -9=fitting not successful or no uncertainty given Column 19: Mean value of measured data inside fitting window [same units as measurements] Column 20: Climatological station pressure [mbar] Column 21: Data processing type index Column 22: Calibration file version Column 23: Calibration file validity starting date Column 24: Level 2 Fit data quality flag: 0=assured high quality, 1=assured medium quality, 2=assured low quality, 10=not-assured high quality, 11=not-assured medium quality, 12=not-assured low quality Column 25: Sum over 2^i using those i, for which the corresponding L2Fit data quality parameter exceeds the DQ1 limit, 0=L1 data quality above 0, 1=Spectral fitting was not successful, 2=Weighted rms of spectral fitting too large, 3=Wavelength shift too large Column 26: Sum over 2^i using those i, for which the corresponding L2Fit data quality parameter exceeds the DQ2 limit (same parameters as for DQ1) Column 27: Level 1 data quality flag: 0=assured high quality, 1=assured medium quality, 2=assured low quality, 10=not-assured high quality, 11=not-assured medium quality, 12=not-assured low quality Column 28: Sum over 2^i using those i, for which the corresponding L1 data quality parameter exceeds the DQ1 limit, 0=Saturated data, 1=Too few dark counts measurements, 2=No temperature given or effective temperature too different from the reference temperature, 3=Dark count too high, 4=Unsuccessful dark background fitting, 5=Absolute value of estimated average residual stray light level too high, 6=Although attempted, no wavelength change could be retrieved, 7=Absolute value of retrieved wavelength shift too large, 8=Retrieved wavelength shift differs too much from the shift predicted by the effective temperature Column 29: Sum over 2^i using those i, for which the corresponding L1 data quality parameter exceeds the DQ2 limit (same parameters as for DQ1) Column 30: Wavelength effective temperature [�C], 999=no effective temperature given Column 31: Estimated average residual stray light level [%] (only valid for stray light correction methods 2 and higher) Column 32: Retrieved wavelength shift from level 1 data [nm], -9=no wavelength change determination Column 33: Retrieved wavelength shift from spectral fitting [nm], -9=no wavelength change fitting Column 34: Integration time [ms] Column 35: Number of dark count cycles Column 36: Effective position of filterwheel #1, 0=filterwheel not used, 1-9 are valid positions Column 37: Effective position of filterwheel #2, 0=filterwheel not used, 1-9 are valid positions --------------------------------------------------------------------------------------- 20181126T101552Z 6904.42769 32.14 62.23 137.99 85.08 291.15 8.5187e-02 2.5145e-03 2.138 0.00e+00 0 0 0 0 2.359e-04 1.827e-04 7.550e-05 4.1258e+09 775 2 3 20181126 10 0 0 10 0 0 21.88 0.61 -0.00156 -0.00357 17.6 430 2 4 20181126T101636Z 6904.42820 32.17 62.12 138.14 85.23 291.22 8.6831e-02 1.3378e-03 2.130 0.00e+00 0 0 0 0 2.266e-04 9.714e-05 7.602e-05 4.0671e+09 775 2 3 20181126 10 0 0 10 0 0 21.88 0.62 -0.00154 -0.00344 17.3 437 2 4 20181126T101720Z 6904.42871 32.24 62.01 138.29 85.37 291.30 8.0801e-02 3.0729e-03 2.123 0.00e+00 0 0 0 0 1.934e-04 2.214e-04 7.960e-05 3.7157e+09 775 2 3 20181126 10 0 0 10 0 0 21.88 0.62 -0.00134 -0.00337 18.7 406 2 4 20181126T101804Z 6904.42921 32.25 61.90 138.45 85.52 291.38 7.5402e-02 3.7567e-03 2.116 0.00e+00 0 0 0 0 1.924e-04 2.699e-04 7.954e-05 3.7050e+09 775 2 3 20181126 10 0 0 10 0 0 21.98 0.61 -0.00131 -0.00332 19.3 393 2 4 20181126T101848Z 6904.42972 32.12 61.80 138.60 85.66 291.46 7.3074e-02 4.6694e-03 2.108 0.00e+00 0 0 0 0 1.949e-04 3.340e-04 7.938e-05 3.7260e+09 775 2 3 20181126 10 0 0 10 0 0 21.98 0.61 -0.00126 -0.00333 20.2 376 2 4 20181126T102220Z 6904.43218 32.21 61.29 139.33 86.36 291.83 7.7763e-02 2.6556e-03 2.074 0.00e+00 0 0 0 0 2.149e-04 1.872e-04 7.559e-05 4.1162e+09 775 2 3 20181126 10 0 0 10 0 0 21.88 0.61 -0.00133 -0.00343 17.1 443 2 4 20181126T102305Z 6904.43270 32.28 61.18 139.49 86.50 291.92 6.1693e-02 2.0919e-03 2.067 0.00e+00 0 0 0 0 2.067e-04 1.472e-04 7.778e-05 3.8893e+09 775 2 3 20181126 10 0 0 10 0 0 21.88 0.62 -0.00147 -0.00337 18.0 422 2 4 20181126T102349Z 6904.43321 32.65 61.07 139.65 86.65 291.99 6.9311e-02 2.7602e-03 2.060 0.00e+00 0 0 0 0 1.932e-04 1.933e-04 7.793e-05 3.8661e+09 775 2 3 20181126 10 0 0 10 0 0 21.88 0.62 -0.00130 -0.00319 18.7 406 2 4 20181126T102434Z 6904.43373 32.63 60.97 139.81 86.80 292.07 8.6315e-02 1.8517e-03 2.054 0.00e+00 0 0 0 0 2.313e-04 1.296e-04 7.701e-05 3.9533e+09 775 2 3 20181126 10 0 0 10 0 0 21.88 0.62 -0.00141 -0.00321 18.0 420 2 4 20181126T102518Z 6904.43424 33.25 60.86 139.96 86.94 292.15 8.3879e-02 1.7818e-03 2.047 0.00e+00 0 0 0 0 2.218e-04 1.241e-04 7.609e-05 4.0593e+09 775 2 3 20181126 10 0 0 10 0 0 21.88 0.62 -0.00151 -0.00318 17.9 422 2 4 20181126T102855Z 6904.43675 32.17 60.36 140.74 87.65 292.54 6.8953e-02 1.7801e-03 2.015 0.00e+00 0 0 0 0 2.005e-04 1.220e-04 8.525e-05 3.2319e+09 775 2 3 20181126 10 0 0 10 0 0 21.88 0.61 -0.00146 -0.00320 21.1 360 2 4 20181126T102939Z 6904.43726 32.15 60.25 140.89 87.79 292.62 7.4838e-02 3.3267e-03 2.009 0.00e+00 0 0 0 0 2.090e-04 2.273e-04 8.618e-05 3.1564e+09 775 2 3 20181126 10 0 0 10 0 0 21.88 0.61 -0.00144 -0.00309 22.5 337 2 4 20181126T103023Z 6904.43777 32.28 60.15 141.05 87.93 292.70 7.7249e-02 3.3359e-03 2.003 0.00e+00 0 0 0 0 2.002e-04 2.267e-04 8.018e-05 3.6459e+09 775 2 3 20181126 10 0 0 10 0 0 21.88 0.61 -0.00143 -0.00309 20.5 371 2 4 20181126T103107Z 6904.43828 32.20 60.05 141.21 88.08 292.78 8.1582e-02 2.7337e-03 1.997 0.00e+00 0 0 0 0 1.909e-04 1.857e-04 7.777e-05 3.8824e+09 775 2 3 20181126 10 0 0 10 0 0 21.88 0.62 -0.00141 -0.00301 18.3 415 2 4 20181126T103151Z 6904.43879 32.14 59.95 141.37 88.22 292.86 5.9658e-02 1.9235e-03 1.991 0.00e+00 0 0 0 0 1.922e-04 1.301e-04 7.570e-05 4.1000e+09 775 2 3 20181126 10 0 0 10 0 0 21.88 0.61 -0.00144 -0.00310 18.3 414 2 4 20181126T103521Z 6904.44122 32.22 59.47 142.14 88.90 293.25 8.6088e-02 1.9366e-03 1.963 0.00e+00 0 0 0 0 2.235e-04 1.296e-04 7.388e-05 4.3015e+09 775 2 3 20181126 10 0 0 10 0 0 21.88 0.61 -0.00134 -0.00316 16.7 454 2 4 20181126T103605Z 6904.44173 32.12 59.38 142.30 89.04 293.33 8.6975e-02 1.8767e-03 1.957 0.00e+00 0 0 0 0 2.032e-04 1.248e-04 7.309e-05 4.4038e+09 775 2 3 20181126 10 0 0 10 0 0 21.88 0.62 -0.00139 -0.00304 16.5 460 2 4 20181126T103649Z 6904.44224 32.34 59.28 142.47 89.18 293.41 7.1906e-02 1.4919e-03 1.952 0.00e+00 0 0 0 0 1.972e-04 9.903e-05 7.230e-05 4.4976e+09 775 2 3 20181126 10 0 0 10 0 0 21.88 0.62 -0.00137 -0.00297 16.0 472 2 4 20181126T103733Z 6904.44274 32.24 59.18 142.63 89.33 293.49 7.7980e-02 1.8454e-03 1.946 0.00e+00 0 0 0 0 1.848e-04 1.220e-04 7.314e-05 4.3920e+09 775 2 3 20181126 10 0 0 10 0 0 21.88 0.62 -0.00123 -0.00294 16.5 460 2 4 20181126T103817Z 6904.44325 32.23 59.08 142.79 89.47 293."; // result will be an iterator over tuples containing the start and end indices for each match in the string let result = regex.captures_iter(string); for mat in result { println!("{:?}", mat); } }

Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for Rust, please visit: https://docs.rs/regex/latest/regex/