This is makeindex, version 2.15 [TeX Live 2020] (kpathsea + Thai support).
Scanning input file CoursElectriciteMagnetisme.idx.....done (1048 entries accepted, 0 rejected).
Sorting entries...........done (11798 comparisons).
Generating output file CoursElectriciteMagnetisme.ind....done (407 lines written, 0 warnings).
Output written in CoursElectriciteMagnetisme.ind.
Transcript written in CoursElectriciteMagnetisme.ilg.