Bash script to traverse through a directory, recursing with a call to a function that finds and replaces specific text.

recurse_and_replace.sh

# ************************************************************* #
# ************************ GITHUB GIST ************************ # 
# ************************************************************* #
# recurse_and_replace.sh
# Bash script to traverse through a directory, recursing with a call to a function that finds and replaces specific text.
#                                      ###########################
# LICENSE                                                        #
# *******                                                        #
# The code in this gist is public domain.                        #
# Licensed as Public Domain CC0 ##################################
##################################################################

# MAKE EDITS AS NEEDED
# *************************************************************
#!/bin/bash
# recurse_and_replace
# Traverse through a folder or directory using a recursive function to find and replace text.
  # NOTE - best to call from directory where this script is located.
  # NOTE - add and/or delete as needed. This is just the base. 
  # See test_recurse_and_replace.sh for a use example.

# Start traversing from the directory defined in variable.
traverse_directory="."
script_filename="$0"

# Set a global old and new text variables.
_old_text="NAME"
_new_text="NEW NAME"


# Function to replace strings in files
find_text() {
  # file found and assign to variable
  local file="$1"
  
  # check if the file has any _old_text
  local count=$(grep -o "$_old_text" "$file" | wc -l)

  # if file has _old_text
  if [ "$count" -gt 0 ]; then
    # replace the contents
    sed "s|$_old_text|$_new_text|g" "$file"
    
    # Get the relative path of the file
    relative_path=$(realpath --relative-to="$traverse_directory" "$file")
    
    # log files changed and count to found_pages.log
    echo "File: $relative_path" >> found_pages.log
    echo "Occurrences: $count" >> found_pages.log
    echo >> found_pages.log
 fi
}

# Function that recurses to traverse directories, find old text, replace with new text.
traverse_directories() {
  # using function defined at top of script
  local dir="$1"

  # Loop through each file and directory in current folder of directory.
  for item in "$dir"/*; do
    if [ -f "$item" ]; then
   # make sure to exclude this file 
   # not concrete so best to call this script from the directory it is in
   if [[ "$traverse_directory" = "." && "$item" = "$script_filename" ]]; then
        echo Probably this file - so skipping replace text function call.
      else
        # if file call find_text()
        find_text "$item"
      fi
    elif [ -d "$item" ]; then
      # if it's a folder recurse
      traverse_directories "$item"
    fi
  done
}

# Add or clear the log file.
if [ -e found_pages.log ]; then
  # clear log file
  > found_pages.log
else
  # create a log file
  touch found_pages.log
fi

# Finally call the recursing function.
traverse_directories "$traverse_directory"



# This gist is meant to work as a general idea, guide, or 
# starting point. Use as needed and/or see fit.
# *************************************************************
# *************************************************************

zz.support - chmod.txt

************************ SUPPORT FILE ************************
* chmod.txt
* Test File - using regular expression to replace special characters.

NOTE - in example this is in recurse_and_replace/tldr folder with copied file prefixed "_original-".
*****************************************
chmod
[0mChange the access permissions of a file or directory.More information: https://www.gnu.org/software/coreutils/chmod.

 - [23;22;24;25;32mGive the [u]ser who owns a file the right to e[x]ecute it:
[23;22;24;25;33m   chmod u+x {{file}}
[0m
 - [23;22;24;25;32mGive the [u]ser rights to [r]ead and [w]rite to a file/directory:
[23;22;24;25;33m   chmod u+rw {{file_or_directory}}
[0m
 - [23;22;24;25;32mRemove e[x]ecutable rights from the [g]roup:
[23;22;24;25;33m   chmod g-x {{file}}
[0m
 - [23;22;24;25;32mGive [a]ll users rights to [r]ead and e[x]ecute:
[23;22;24;25;33m   chmod a+rx {{file}}
[0m
 - [23;22;24;25;32mGive [o]thers (not in the file owner's group) the same rights as the [g]roup:
[23;22;24;25;33m   chmod o=g {{file}}
[0m
 - [23;22;24;25;32mRemove all rights from [o]thers:
[23;22;24;25;33m   chmod o= {{file}}
[0m
 - [23;22;24;25;32mChange permissions recursively giving [g]roup and [o]thers the ability to [w]rite:
[23;22;24;25;33m   chmod -R g+w,o+w {{directory}}
[0m
 - [23;22;24;25;32mRecursively give [a]ll users [r]ead permissions to files and e[X]ecute permissions to sub-directories within a directory:
[23;22;24;25;33m   chmod -R a+rX {{directory}}
[0m[0m

* This file is support for this gist and is meant to serve as a
* test, way of implementation, or an additional explanation for 
* the main gist file.
****************************************************************
****************************************************************

zz.support - lecture.txt

************************ SUPPORT FILE ************************
* lecture.txt
* Test File - for specifying specific text to be replaced.

NOTE - in example this is in recurse_and_replace root folder with copied file prefixed "_original-".

Alright, class, let's delve into the vast world of computer science, shall we? This field is as diverse 
as it is fascinating, touching on everything from the theory behind how computers work to the practical 
applications through programming languages. 

### Introduction to Computer Science:

**Computer science** is the study of computers and computational systems. It involves understanding how 
computers function, how data is processed and stored, and how to develop software to solve real-world problems.

### Programming Languages:

Now, programming languages are the tools we use to communicate with computers. Here are a few:

1. **Python**: Known for its simplicity and readability, Python is great for beginners. It’s used in web 
development, data analysis, artificial intelligence (AI), and scientific computing. For example, you can 
write a simple program to print "Hello, World!" like this:

   ```python
   print("Hello, World!")
   ```

2. **Java**: It's used in developing Android apps, enterprise-level applications, and large systems. Here's a 
basic Java program that prints the same message:

   ```java
   public class HelloWorld {
       public static void main(String[] args) {
           System.out.println("Hello, World!");
       }
   }
   ```

3. **JavaScript**: Primarily used for web development, JavaScript adds interactivity to websites. You can 
create pop-ups or modify webpage content dynamically. Here's a simple script that displays an alert:

   ```javascript
   alert("Hello, World!");
   ```

4. **C++**: This language is used for systems/software development, gaming, and high-performance applications. 
It’s known for its speed and performance. Here’s an example printing "Hello, World!" in C++:

   ```cpp
   #include <iostream>
   using namespace std;

   int main() {
       cout << "Hello, World!" << endl;
       return 0;
   }
   ```

### Applications in Computer Science:

In computer science, these languages and many others are tools we use to create software that solves problems. 
For instance:
- **Web Development**: JavaScript, HTML, and CSS are used to create interactive and visually appealing websites.
- **Data Analysis**: Python with libraries like Pandas and NumPy helps process and analyze large sets of data.
- **Mobile App Development**: Java and Kotlin for Android, Swift for iOS, enable us to build mobile applications.

### Conclusion:

This introductory glimpse into computer science barely scratches the surface. It's a vast field with countless 
possibilities and applications. As you progress, you’ll explore algorithms, data structures, cybersecurity, 
artificial intelligence, and so much more. So, buckle up and get ready for an exciting journey through the 
world of computers and technology!

* This file is support for this gist and is meant to serve as a
* test, way of implementation, or an additional explanation for 
* the main gist file.
****************************************************************
****************************************************************

zz.support - recurse_and_replace.log

************************ SUPPORT FILE ************************
* recurse_and_replace.log
* The log file that documents relative path and number of occurances.

File: lecture.txt
Occurrences of Computer Science:: 2

File: man/tldr.txt
Occurrences of NAME: 1

File: musical.txt
Occurrences of Title: "New York, New York": 1

File: recurse_and_replace.log
Occurrences of Computer Science:: 1

File: tldr/chmod.txt
Occurrences of Regular Expression: 0



* This file is support for this gist and is meant to serve as a
* test, way of implementation, or an additional explanation for 
* the main gist file.
****************************************************************
****************************************************************

zz.support - test_recurse_and_replace.log

************************ SUPPORT FILE ************************
* test_recurse_and_replace.log
* Condensed terminal output from the test file test_recurse_and_replace.sh


1 --------------------------

NOTE - in example this is in recurse_and_replace root folder with copied file prefixed "_original-".

Alright, class, let's delve into the vast world of computer science, shall we? This field is as diverse 
as it is fascinating, touching on everything from the theory behind how computers work to the practical 
applications through programming languages. 

### Introduction to Computer Science - LECURE I SUMMER SEMESTER

**Computer science** is the study of computers and computational systems. It involves understanding how 
computers function, how data is processed and stored, and how to develop software to solve real-world problems.

### Programming Languages:

Now, programming languages are the tools we use to communicate with computers. Here are a few:



2 --------------------------

NOTE - in example this is in recurse_and_replace/man folder with copied file prefixed "_original-".
*****************************************
TLDR(1)                                                                                                      User Commands                                                                                                      TLDR(1)

NEW CHANGED NAME - it worked
       tldr - manual page for tldr 0.4.0.1

SYNOPSIS
       tldr [-v|--version] [--update] COMMAND

DESCRIPTION
       tldr - Simplified and community-driven man pages

              tldr Client program



3 --------------------------

NOTE - in example this is in recurse_and_replace root folder with copied file prefixed "_original-".

### Title: "Echos of New York"

#### Act 1: Small Town Dreams and City Life

**Scene 1: The Departure**

*Setting: A small town in the late 1940s. Family and friends are gathered at the train station to bid farewell to the young man.*

**Song: "New York, New York"**

**Young Man**: (to his family) "I know it's a big step, but New York is where dreams come true. I've got to take my shot."

**Family Member**: "We'll miss you, but we believe in you. Go make us proud."


1 --------------------------

File: lecture.txt
Occurrences of Computer Science - LECURE I SUMMER SEMESTER: 2

File: man/tldr.txt
Occurrences of NAME: 1

File: musical.txt
Occurrences of Title: "New York, New York": 1



1 --------------------------



4 --------------------------

NOTE - in example this is in recurse_and_replace/tldr folder with copied file prefixed "_original-".
*****************************************
chmod
Change the access permissions of a file or directory.More information: https://www.gnu.org/software/coreutils/chmod.

Give the [u]ser who owns a file the right to e[x]ecute it:
   chmod u+x {{file}}

Give the [u]ser rights to [r]ead and [w]rite to a file/directory:
   chmod u+rw {{file_or_directory}}

Remove e[x]ecutable rights from the [g]roup:
   chmod g-x {{file}}

Give [a]ll users rights to [r]ead and e[x]ecute:



* This file is support for this gist and is meant to serve as a
* test, way of implementation, or an additional explanation for 
* the main gist file.
****************************************************************
****************************************************************

zz.support - test_recurse_and_replace.sh

************************ SUPPORT FILE ************************
* test_recurse_and_replace.sh
* An example of running recurse_and_replace.sh where additional conditions and variables were added in order to display different use cases.

#!/bin/bash
# test_recurse_and_replace
# Traverse through a folder or directory using a recursive function to find and replace text.
  # NOTE - best to call from directory where this script is located.
  # NOTE - example has extra conditions and variables commented above -> *-FOR-EXAMPLE-*

# Start traversing from the directory defined in variable.
traverse_directory="recurse_and_replace"
script_filename="$0"

# *-FOR-EXAMPLE-*
skip_files="_original"

# Set a global uri variables with old and new uri
_old_text="per     CONDITION"
_new_text="CHANGED per condition"


# Function to replace strings in files
find_text() {
  # file found and assign to variable
  local file="$1"
  local folder="$2"
  # *-FOR-EXAMPLE-*
  local reg_ex_it=0
  if [ -e "$folder" ]; then
    folder="normal_run"
  else 
    # *-FOR-EXAMPLE-* [1], [2], [3], and [4]
    if [ "$folder" = "man" ]; then
    # [2]
   echo && echo 2 -------------------------- && echo
      _old_text="NAME"
      _new_text="NEW CHANGED NAME - it worked"
    elif [ "$folder" = "tldr" ]; then
    # [4]
      echo && echo 4 -------------------------- && echo
      _old_text="Regular Expression"
      _new_text=""
      reg_ex_it=1
    else
    # [1] and [3] $folder = "normal_run"
      if [ "$(echo $file | sed "s|.*/||" )" = "musical.txt" ]; then
      # [3]
     echo && echo 3 -------------------------- && echo
        _old_text="Title: \"New York, New York\""
        _new_text="Title: \"Echos of New York\""
      else 
      # [1]
     echo && echo 1 -------------------------- && echo
        _old_text="Computer Science:"
        _new_text="Computer Science - LECURE I SUMMER SEMESTER"
      fi
    fi
  fi
  # check if the file has any _old_text
  local count=$(grep -o "$_old_text" "$file" | wc -l)

  # if file has _old_text
  if [[ "$count" -gt 0 || $reg_ex_it = 1 ]]; then
    
 # *-FOR-EXAMPLE-*
    if [ $reg_ex_it = 1 ]; then
      sed -E "s|^(.*)([0-9;]+)m||g" "$file" | head -n 15
    else
      # replace the contents
      sed "s|$_old_text|$_new_text|g" "$file" | head -n 15
    fi
   
    # Get the relative path of the file
    relative_path=$(realpath --relative-to="$traverse_directory" "$file")
   
    # log files changed and count to found_pages.log
    echo "File: $relative_path" >> $traverse_directory/recurse_and_replace.log
    
                      # *-FOR-EXAMPLE-*
    echo "Occurrences of $_old_text: $count" >> $traverse_directory/recurse_and_replace.log
 
    echo >> $traverse_directory/recurse_and_replace.log
  fi
}

# Function that recurses to traverse directories, find old text, replace with new text.
traverse_directories() {
  
  # using function defined at top of script
  local dir="$1"  
  # Loop through each file and directory in current folder of directory.
  for item in "$dir"/*; do
    if [ -f "$item" ]; then
      # make sure to exclude this file 
      # not concrete so best to call this script from the directory it is in
   if [[ "$traverse_directory" = "." && "$item" = "$script_filename" ]]; then
        echo Probably this file - so skipping replace text function call.
      else
        # skip prefixed file
        # *-FOR-EXAMPLE-*
        check_if_skip_file=$(echo $item | sed -e "s|$dir/||" -e s/.txt// -e s/-.*//)
        if [ ! "$check_if_skip_file" = "$skip_files" ]; then
          # *-FOR-EXAMPLE-* [1 [a][b]], [2], amd [3]
          if [ "$dir" = "$traverse_directory/man" ]; then
          # [2]
            # if file call find_text()
            find_text "$item" "man" && echo
          elif [ "$dir" = "$traverse_directory/tldr" ]; then
          # [4]
            find_text "$item" "tldr" && echo 
          else 
          # [1] and [3]
            find_text "$item" && echo
          fi
        fi 
      fi
    elif [ -d "$item" ]; then
      # if it's a folder recurse
      traverse_directories "$item"
    fi
  done
}

# Add or clear the log file.
if [ -e found_pages.log ]; then
  # clear log file
  > $traverse_directory/recurse_and_replace.log
else
  # create a log file
  touch $traverse_directory/recurse_and_replace.log
fi

# Finally call the recursing function.
traverse_directories "$traverse_directory"


* This file is support for this gist and is meant to serve as a
* test, way of implementation, or an additional explanation for 
* the main gist file.
****************************************************************
****************************************************************

zz.support - tldr.txt

************************ SUPPORT FILE ************************
* tldr.txt
* Test File - for specifying specific text to be replaced.

NOTE - in example this is in recurse_and_replace/man folder with copied file prefixed "_original-".
*****************************************
TLDR(1)                                                                                                      User Commands                                                                                                      TLDR(1)

NAME
       tldr - manual page for tldr 0.4.0.1

SYNOPSIS
       tldr [-v|--version] [--update] COMMAND

DESCRIPTION
       tldr - Simplified and community-driven man pages

              tldr Client program

   Available options:
       -h,--help
              Show this help text

       -v,--version
              Show version

       --update
              Update tldr pages

       COMMAND
              name of the command

tldr 0.4.0.1                                                                                                 February 2020                                                                                                      TLDR(1)


* This file is support for this gist and is meant to serve as a
* test, way of implementation, or an additional explanation for 
* the main gist file.
****************************************************************
****************************************************************