Say you have files like this:
lecture1.tex lecture2.tex lecture3.tex ... lecture13.tex lecture24.tex
and need to add a new lecture5! Maybe each file further comes with an header labelled after its numbering (say for lecture8.tex):
\chapter{Lecture 8 --- Complexity \& Interpretation of Quantum Mechanics}
\label{L8}
So if we want to add one file, all lectures from the old lecture5 onward should be moved one integer up (lecture5 becomes lectures6, etc.) and the headers also corrected accordingly.
The moving of files can be instructed with Mathematica:
Table["mv lecture" <> ToString[i] <> ".tex lecture" <>
ToString[i + 1] <> ".tex", {i, 24, 5, -1}] // TableForm
and copied/pasted as Plain Text (right-click) into a bash file:
#!/bin/bash mv lecture24.tex lecture25.tex mv lecture23.tex lecture24.tex mv lecture22.tex lecture23.tex mv lecture21.tex lecture22.tex mv lecture20.tex lecture21.tex mv lecture19.tex lecture20.tex mv lecture18.tex lecture19.tex mv lecture17.tex lecture18.tex mv lecture16.tex lecture17.tex mv lecture15.tex lecture16.tex mv lecture14.tex lecture15.tex mv lecture13.tex lecture14.tex mv lecture12.tex lecture13.tex mv lecture11.tex lecture12.tex mv lecture10.tex lecture11.tex mv lecture9.tex lecture10.tex mv lecture8.tex lecture9.tex mv lecture7.tex lecture8.tex mv lecture6.tex lecture7.tex mv lecture5.tex lecture6.tex
Then to increment the labeling in the files themselves, assuming that follows the structure I gave, that does it for one file (1st line the Chapter, 2nd the label):
perl -pi.bak -e 's/(\\chapter\{Lecture )(\d+)/$1.($2+1)/ge;' lecture8.tex
perl -pi.bak -e 's/(\\label\{L)(\d+)/$1.($2+1)/ge;' lecture8.tex
so for all files:
for f in lecture*.tex; do perl -pi.bak -e 's/(\\chapter\{Lecture )(\d+)/$1.($2+1)/ge;' "$f"; done
for f in lecture*.tex; do perl -pi.bak -e 's/(\\label\{L)(\d+)/$1.($2+1)/ge;' "$f"; done