functions()

Below is an in-depth documentation for the functions() function. This explanation covers its purpose, internal logic, variables used, and the overall workflow step by step.

In-Depth Documentation for the functions() Function

1. Purpose and Overview

The functions() function is responsible for scanning source files and extracting the function dependencies required by the main script. Its primary tasks include:

• Parsing input lines: It reads each line from a given source file (referenced by the variable fncfile).

• Identifying function declarations and calls: It checks whether a line contains a function definition or a reference to a needed function.

• Managing dependencies: It updates various global variables and arrays such as FNCNEED, FNCDEP, INFUNCTION, and FNCOPENFILE to keep track of functions that are required or have already been found.

• Invoking the indexing process: Once a function is identified or its dependencies resolved, it calls the index_function() (described separately) to register and process the function’s code.

The overall goal is to ensure that every function used within the script is properly recognized, indexed, and its dependencies handled so that the resulting module or library is consistent and complete.

2. Internal Logic and Workflow

The function proceeds in several distinct phases:

2.1. Skipping Initial Arguments

while [ -n "$1" ]; do shift done

• Purpose:
  This loop simply shifts through all initial arguments until none remain.

• Explanation:
  It seems that the function is designed to ignore any passed parameters before processing the main file content. This may be because the actual work relies on reading from a file (stored in the variable fncfile).

2.2. Reading and Processing Each Line

while read line ; do FNCFOUND="" COMMENTLINE="" FNCLINE=$line set -- $line [ "${1:0:1}" = "#" ] && COMMENTLINE=$FNCLINE FNCEND="`echo ''$FNCLINE''|awk '{print $1}'|grep "}"`" FNCBRACE="`echo ''$FNCLINE''|sed 's/function //'|awk '{print $1}'|grep "()"|sed 's/()//'`"

• Purpose:
  The function then enters a loop, reading the file line by line.

• Variables Introduced:

  • line and FNCLINE: The current line being processed.

  • FNCFOUND: Initialized as empty; used later to accumulate any function names found in the line.

  • COMMENTLINE: Used to mark if the current line is a comment.

• Key Steps:

  • Detecting Comments:
    It checks if the first character of the line is # and, if so, assigns the line to COMMENTLINE.

  • Identifying End of Function:
    It uses an awk and grep pipeline to check if the line contains a closing curly brace (}), storing the result in FNCEND.

  • Extracting Function Name:
    The command for FNCBRACE strips out the literal string "function ", then uses awk and grep to extract a pattern ending in (), and finally removes the parentheses. This determines if the line is starting a new function declaration.

2.3. Processing Lines Depending on Their Content

The next part of the function branches based on whether the current line represents a function definition or is simply a part of a function call/dependency.

2.3.1. When the Line is Not Part of an Outgoing Function or a Comment

if [ -z "$OUTFUNCTION" ] | [ -z "$COMMENTLINE" ]; then

• Purpose:
  This condition checks whether the line is not part of an "out" function (i.e. an external or already handled function) and is not a comment.

• Explanation:
  If either OUTFUNCTION is empty or the line is not a comment, the function proceeds to scan for dependencies.

2.3.1.1. Scanning for Dependencies

for fncdepend in $FNCNEED $FNCDEP ; do FNCTRACE="`echo ''$FNCLINE''|grep "$fncdepend"`" if [ ! -z "$FNCTRACE" ]; then FNCFOUND="$FNCFOUND $fncdepend " fi done

• Purpose:
  The loop goes through every function name in the combined lists of FNCNEED (functions that are needed) and FNCDEP (functions that are dependencies).

• Internal Logic:

  • For each candidate dependency (fncdepend), the function searches for its occurrence within the current line (FNCLINE) using grep.

  • If found (FNCTRACE is not empty), the dependency is appended to FNCFOUND.

• Result:
  FNCFOUND will contain one or more function names that the current line refers to.

2.3.1.2. Handling Found Functions

if [ ! -z "$FNCFOUND" ]; then echo "Fonction nécessaire" if [ ! -z "$FNCBRACE" ]; then INFUNCTION[${#INFUNCTION[@]}]="$FNCBRACE" FNCOPENFILE="$FNCOPENFILE ${FNCBRACE} " FNCDEP="$FNCDEP ${FNCBRACE} " FNCNEED="`echo ''$FNCNEED''|sed 's/ '"${FNCBRACE}"' / /g'`" # on enregistre la fonction # index_function fi else if [ ! -z "$FNCEND" ]; then echo "$FNCEND" unset INFUNCTION[${#INFUNCTION[@]}-1] echo "fin de la fonction" fi fi

• Explanation:

  • If Dependencies Are Found (FNCFOUND is not empty):

    • The message "Fonction nécessaire" is printed.

    • If FNCBRACE (the detected function name) is present, then:

      • The function is added to the INFUNCTION array.

      • FNCOPENFILE is updated to include this function.

      • The function name is also appended to FNCDEP because once detected, it becomes a dependency.

      • Finally, the found function is removed from FNCNEED using sed so that it is not redundantly processed.

  • If No Dependency Is Found:

    • The function checks if FNCEND is set (indicating the end of a function block).

    • If so, it prints FNCEND, unsets (removes) the last function from INFUNCTION (i.e. closes the current function context), and outputs "fin de la fonction".

2.3.2. Handling Lines When INFUNCTION Is Not Empty

elif [ ! -z "`echo ${INFUNCTION[@]}`" ]; then

• Purpose:
  This branch handles the case where the line is part of an active function (i.e. INFUNCTION is not empty).

• Internal Logic:

  • For each function found in FNCFOUND, the function:

    • Initializes a flag INDOING to 0.

    • Loops over the current INFUNCTION array to check if the function has already been processed.

    • If a match is found, INDOING is set to 1.

  • Decision Making:

    • If INDOING is not zero (the function was already processed), then the found function is removed from FNCFOUND.

    • Otherwise, it loops over FNCDEP to check if the found function is already in the dependency list.

      • If not, it is added to FNCDEP.

2.3.3. Handling When OUTFUNCTION Is Not Empty

elif [ ! -z "$OUTFUNCTION" ]; then echo "outfonction"

• Purpose:
  If the global variable OUTFUNCTION is not empty, the script indicates that the current line is within a function that does not require additional processing ("outfonction").

2.3.4. Handling the Module Context

else if [ "$FNCTRACE" = "$infunction" ]; then echo "en fonction" fi fi

• Purpose:
  This final else block handles any remaining situation, possibly when the line belongs to a module context.

• Explanation:
  It performs a basic check by comparing FNCTRACE to a variable infunction (likely set elsewhere) and prints "en fonction" if they match.

2.4. Final Step: Indexing the Function

index_function done < "$fncfile"

• Purpose:
  After processing each line from the file (whose name is stored in the variable fncfile), the function index_function() is called.

• Explanation:
  This call ensures that once the current line has been processed for dependencies, the indexing mechanism is updated accordingly. The index_function() function handles file creation, logging, and the registration of the function block.

3. Variables and Their Roles

• FNCLINE:
  Holds the current line read from the file. It is used for pattern matching and is echoed for debugging.

• FNCFOUND:
  A temporary variable to accumulate function names found in the current line that match dependencies.

• COMMENTLINE:
  Used to flag whether the current line is a comment. If the first character is a #, it is set.

• FNCEND:
  Contains the result of checking whether the line signals the end of a function block (e.g., containing a }).

• FNCBRACE:
  Extracts the function name from a line that declares a function. It uses text-processing commands to strip unwanted characters and identify a new function declaration.

• FNCNEED and FNCDEP:
  Global variables that list:

  • FNCNEED: Functions that are needed but not yet processed.

  • FNCDEP: Functions that are already determined as dependencies.

• INFUNCTION:
  An array holding functions that are currently active (i.e., those that are being defined or processed).

• FNCOPENFILE:
  A string that aggregates the function names that have been opened; used for further processing or module creation.

• OUTFUNCTION:
  Likely holds functions that are marked as external or already processed in another context.

• INDOING:
  A flag used within loops to determine if a function from FNCFOUND has already been handled in the INFUNCTION array.

• fncfile:
  The source file from which the function definitions and calls are being read.

4. Overall Workflow Summary

1. Skip Input Arguments:
   The function first discards any passed parameters using a loop of shift.

2. Line-by-Line Processing:
   The function reads each line from fncfile and initializes helper variables.

   • Detect Comments:
     If the line starts with #, it is flagged as a comment.

   • Identify Function Boundaries:
     Use awk, sed, and grep to detect function start (FNCBRACE) and end (FNCEND) markers.

3. Dependency Scanning:

   • For each needed function (from FNCNEED and FNCDEP), check if the current line references it.

   • If found, mark it in FNCFOUND.

4. Handling Function Declaration:

   • If a dependency is found and a new function is being declared (FNCBRACE is set):

     • Append the function to the INFUNCTION array.

     • Update FNCOPENFILE and FNCDEP.

     • Remove the function from FNCNEED to avoid duplicate processing.

   • Otherwise, if the line signals the end of a function block, remove the last function from INFUNCTION and log the end.

5. Handling Active Functions:

   • If INFUNCTION is not empty, check each function found in FNCFOUND to avoid duplicate processing.

   • Update FNCDEP for any new dependency not already listed.

6. Handling External Functions:

   • If OUTFUNCTION is set, simply indicate that the line belongs to an external function context.

7. Final Indexing:

   • After processing each line, the function calls index_function() to update the function indexing system with the current state.

5. Conclusion

The functions() function is a critical component of the script’s modular design. It:

• Reads each line from the source file to identify function declarations and dependencies.

• Differentiates between comments, function starts, and function ends.

• Maintains several arrays and variables to track which functions are needed, which are already processed, and which are active.

• Calls index_function() to ensure that the extracted information is properly indexed and recorded.

This detailed breakdown should help developers understand every aspect of the functions() function, making it easier to maintain, extend, or debug as needed.