summaryrefslogtreecommitdiff
path: root/reference/CPLUSPLUS/EXAMPLES/MGREP.CC
diff options
context:
space:
mode:
Diffstat (limited to 'reference/CPLUSPLUS/EXAMPLES/MGREP.CC')
-rw-r--r--reference/CPLUSPLUS/EXAMPLES/MGREP.CC854
1 files changed, 854 insertions, 0 deletions
diff --git a/reference/CPLUSPLUS/EXAMPLES/MGREP.CC b/reference/CPLUSPLUS/EXAMPLES/MGREP.CC
new file mode 100644
index 0000000..6052afd
--- /dev/null
+++ b/reference/CPLUSPLUS/EXAMPLES/MGREP.CC
@@ -0,0 +1,854 @@
+/************************************************************************
+ *
+ * Purpose:
+ * Author: M J Leslie
+ * Date: 26-Oct-98
+ *
+ ************************************************************************/
+
+
+/* Known problems.
+
+ Serious memory leaks
+ not enough comments
+ Has problems with vi swp files on Linux (so does normal grep).
+
+*/
+
+
+extern "C"
+{
+#include <stdio.h>
+#include <string.h>
+#include <sys/stat.h>
+#include <ctype.h>
+#include <stdlib.h>
+#include <unistd.h>
+}
+
+#include <iostream.h>
+
+// DEBUG 1 == Debugging information is required.
+// DEBUG 0 == Debugging info is suppresed.
+
+#define DEBUG 0
+
+class List
+{
+public:
+ List()
+ {
+ Reset();
+ }
+
+ ~List()
+ {
+ }
+
+ void Add(int Number)
+ {
+ Add(Number, ':');
+ }
+
+ void Add(int Number, char Prefix)
+ {
+ // Are we adding the first item in the list?
+
+ if ( pFirstItem == 0 )
+ {
+ // Yes.
+
+ pFirstItem = new IntList;
+ pCurrentItem = pFirstItem;
+ }
+ else
+ {
+ // No. Add the number to the end of the list.
+
+ pCurrentItem->pNext = new IntList;
+ pCurrentItem = pCurrentItem->pNext;
+ }
+
+ pCurrentItem->Item = Number;
+ pCurrentItem->Prefix = Prefix;
+ pCurrentItem->pNext = 0;
+ }
+
+ void PointToFirstEntry(void)
+ {
+ pCurrentItem = pFirstItem;
+ }
+
+ void Reset(void)
+ {
+ // This is going to cause seriuos memory leaks!
+
+ pFirstItem = 0;
+ pCurrentItem = 0;
+ }
+
+ int GetCurrentEntry(void)
+ {
+ // Check we have a valid Item.
+
+ if (pCurrentItem)
+ {
+ return (pCurrentItem->Item);
+ }
+ else
+ {
+ // No Item. This could happen when the list is empty.
+
+ return (0);
+ }
+ }
+
+ int GetNextEntry(void)
+ {
+ // Is there another entry in the list?
+
+ if ( pCurrentItem->pNext != 0 )
+ {
+ // Yes. Give it to the caller.
+
+ pCurrentItem = pCurrentItem->pNext;
+
+ return (pCurrentItem->Item);
+ }
+ else
+ {
+ // No.
+
+ return (0);
+ }
+ }
+
+ char GetCurrentPrefix(void)
+ {
+ // pCurrentItem = pCurrentItem->pNext;
+
+ return (pCurrentItem->Prefix);
+ }
+
+ char GetNextPrefix(void)
+ {
+ pCurrentItem = pCurrentItem->pNext;
+
+ return (pCurrentItem->Prefix);
+ }
+
+private:
+
+ struct IntList
+ {
+ int Item;
+ char Prefix;
+ IntList *pNext;
+ };
+
+ IntList *pFirstItem;
+ IntList *pCurrentItem;
+};
+
+class grep
+{
+public:
+
+ // enum { LL = 512 } LineLength ;
+
+ // .......................................................................
+
+ grep() // Constructor.
+ {
+
+ OFF = 0;
+ ON = 1;
+
+ LineNumbering = ON;
+
+ LinesBefore = 2;
+ LinesAfter = 2;
+
+ LinesInFile = 0;
+
+ pFileName = 0;
+
+ SearchString = '\0';
+ InsensitiveSearch = OFF;
+ }
+
+ // .......................................................................
+
+ ~grep () // Distructor.
+ {
+ delete[] pFileName;
+ }
+
+ // .......................................................................
+
+ void BuildMatrix(void)
+ {
+ int Line = 0;
+ int StartPos = 0;
+ int EndPos = 0;
+ int NextPos = 0;
+
+ Debug("BuildMatrix");
+
+ FoundLines.PointToFirstEntry();
+
+ Line = FoundLines.GetCurrentEntry();
+ Debug(Line);
+
+ // Loop until we run out of line numbers.
+
+ while ( Line > 0 )
+ {
+ // Find the first line to display.
+
+ StartPos = Line - LinesBefore;
+
+ if ( StartPos <= EndPos )
+ {
+ StartPos = EndPos + 1;
+ }
+
+ while ( StartPos < Line )
+ {
+ LineMatrix.Add(StartPos, ':');
+ Debug(StartPos, 's');
+ StartPos++;
+ }
+
+ LineMatrix.Add(Line, '*');
+ Debug(Line, '*');
+
+ EndPos = Line + LinesAfter;
+
+ if ( EndPos > LinesInFile )
+ {
+ EndPos = LinesInFile;
+ }
+
+ NextPos = FoundLines.GetNextEntry();
+
+ if ( NextPos > 0 && EndPos >= NextPos )
+ {
+ EndPos = NextPos - 1;
+ }
+
+ Line++;
+
+ while ( Line <= EndPos )
+ {
+ LineMatrix.Add(Line, ':');
+ Debug(Line, 'e');
+ Line++;
+ }
+
+ Line = NextPos;
+ Debug(Line);
+ }
+ }
+
+ // .......................................................................
+
+ void CaseInsensitive(void)
+ {
+ InsensitiveSearch = ON;
+ }
+
+ // .......................................................................
+
+ void Diagnostic(void)
+ {
+ cout << endl << "Extra lines before the found line: " << LinesBefore << endl;
+
+ if ( InsensitiveSearch )
+ {
+ cout << "Search is: Case Insensitive." << endl;
+ }
+ else
+ {
+ cout << "Search is: Case Sensitive." << endl;
+ }
+ }
+
+ // .......................................................................
+
+ int Exists(void)
+ {
+ // Have we got the file name?
+
+ if ( pFileName == 0 )
+ {
+ // No.
+
+ return (0);
+ }
+ else
+
+ {
+ // Yes. Check the file exists.
+
+ struct stat stat_p; /* 'stat_p' is a pointer to a structure
+ * of type 'stat'. */
+
+ /* Get stats for file and place them in
+ * the structure. */
+
+
+ if ( -1 == stat (pFileName, &stat_p) )
+ {
+ // File name not found.
+
+ return (0);
+ }
+
+ if(!S_ISREG(stat_p.st_mode))
+ {
+ // This is not a regular file. It may be a directory.
+ // Ignore it.
+
+ return(0);
+ }
+
+ // File name is OK.
+
+ return (1);
+ }
+ }
+
+ // .......................................................................
+
+ void Name(char *pFN)
+ {
+ Debug("Name", pFN);
+
+ pFileName = new char[strlen(pFN)+1];
+ strcpy(pFileName, pFN);
+ }
+
+ // .......................................................................
+
+ void NoLineNumbers(void)
+ {
+ LineNumbering = OFF;
+ }
+
+
+ // .......................................................................
+
+ void ProcessFile(void)
+ {
+ int Line;
+ int PreviousLine= 0;
+ char Prefix;
+ int CurrentLine = 0;
+ char Buffer[512];
+ int LineCount = 0;
+
+ FILE *fp;
+
+ Debug("ProcessFile");
+
+ cout << endl << "Search String is: " << SearchString << endl;
+ cout << "File Name is: " << pFileName << endl;
+
+ fp = fopen (pFileName, "r");
+
+ LineMatrix.PointToFirstEntry();
+
+ Line = LineMatrix.GetCurrentEntry();
+ Prefix = LineMatrix.GetCurrentPrefix();
+
+ while ( Line > 0 )
+ {
+ do
+ {
+ fgets(Buffer, 512, fp);
+ LineCount ++;
+ } while ( LineCount < Line );
+
+ // Put in a seperator between blocks.
+
+ if ( PreviousLine+1 < Line )
+ {
+ Seperator();
+ }
+
+ if ( LineNumbering )
+ {
+ cout << Line << Prefix << " " << Buffer;
+ }
+ else
+ {
+ cout << Prefix << " " << Buffer;
+
+ }
+
+ PreviousLine = Line;
+
+ Line = LineMatrix.GetNextEntry();
+ Prefix = LineMatrix.GetCurrentPrefix();
+ }
+
+ Seperator();
+
+ fclose(fp);
+ }
+
+ // .......................................................................
+
+ void PutSearchString(char *String)
+ {
+ Debug("PutSearchString");
+ Debug(String);
+
+ SearchString = new char[strlen(String)+1];
+ strcpy(SearchString, String);
+
+ if ( InsensitiveSearch )
+ {
+ // Yes. Convert the buffer to uppercase.
+
+ Uppercase(SearchString);
+ }
+ }
+
+ // .......................................................................
+
+ void Reset(void)
+ {
+ FoundLines.Reset();
+ LineMatrix.Reset();
+ }
+
+ // .......................................................................
+
+ int ScanFile(void)
+ {
+ FILE *fp;
+ char Buffer[512];
+ int LineCounter = 0;
+ int Found = 0; // Number of lines that matched the search string.
+
+ fp = fopen(pFileName, "r");
+
+ Debug ("ScanFile");
+
+ while ( !feof(fp) )
+ {
+ LineCounter++;
+
+ fgets(Buffer, 512, fp);
+
+ // Check the Buffer was big enough.
+
+ if (strlen(Buffer) == 512 -1 )
+ {
+ cout << __FILE__
+ << ": Warning! Lines in "
+ << pFileName
+ << " exceed the max line length of " << 512 << endl;
+ }
+
+ // Are we doing a case insensitive search?
+
+ if ( InsensitiveSearch )
+ {
+ // Yes. Convert the buffer to uppercase.
+
+ Uppercase(Buffer);
+ }
+
+ if ( strstr(Buffer, SearchString) )
+ {
+ FoundLines.Add(LineCounter);
+ Found++;
+ }
+
+ }
+ fclose (fp);
+
+ LinesInFile = LineCounter;
+
+ return(Found);
+ }
+
+ // .......................................................................
+
+ void SetLines(int Lines)
+ {
+ SetLinesBefore(Lines);
+ SetLinesAfter(Lines);
+ }
+
+ // .......................................................................
+
+ void SetLinesBefore(int Lines)
+ {
+ LinesBefore = Lines;
+ }
+
+ // .......................................................................
+
+ void SetLinesAfter(int Lines)
+ {
+ LinesAfter = Lines;
+ }
+
+private:
+
+ // Debugging methods.
+
+ void Debug(char *Message)
+ {
+ if ( DEBUG )
+ {
+ cout << "Debug: " << Message << endl;
+ }
+ }
+
+ // .......................................................................
+ void Debug(int Value)
+ {
+ if ( DEBUG )
+ {
+ cout << "Debug: " << Value << endl;
+ }
+ }
+
+ // .......................................................................
+
+ void Debug(int Value, char Char)
+ {
+ if ( DEBUG )
+ {
+ cout << "Debug: " << Char << " " << Value << endl;
+ }
+ }
+
+ // .......................................................................
+
+ void Debug(char * Str, int Value)
+ {
+ if ( DEBUG )
+ {
+ cout << "Debug: " << Str << " " << Value << endl;
+ }
+ }
+
+ // .......................................................................
+
+ void Debug(char * Str1, char * Str2)
+ {
+ if ( DEBUG )
+ {
+ cout << "Debug: " << Str1 << " " << Str2 << endl;
+ }
+ }
+
+ // .......................................................................
+
+ // Seperate blocks of data.
+
+ void Seperator(void)
+ {
+ cout << "------" << endl;
+ }
+
+ // .......................................................................
+
+
+ void Uppercase(char *String)
+ {
+ int Offset = 0;
+
+ while ( String[Offset] != (char)NULL )
+ {
+ String[Offset] = toupper(String[Offset]);
+ Offset++;
+ }
+ }
+
+ int LineNumbering; // ON = Line numbering required.
+ int LinesBefore;
+ int LinesAfter;
+
+ int LinesInFile; // Number of lines in the file.
+ int InsensitiveSearch; // ON = Case insensitive search required.
+
+ char *pFileName; // File to be searched.
+ char *SearchString;
+
+ List FoundLines; // List of lines that contain the search string.
+ List LineMatrix; // List of lines that will be displayed.
+
+ // Handy variables to set boolean variables.
+
+ int OFF;
+ int ON;
+
+};
+
+// Private functions.
+
+void Debug(char *Message);
+
+void Help(void);
+
+void ProcessTheCommandLine(
+ int argc,
+ char **Argv);
+
+
+//
+// Start point in the program.
+//
+
+main(
+ int Argc,
+ char **Argv)
+{
+ ProcessTheCommandLine(Argc, Argv);
+}
+
+ // .......................................................................
+
+void Help(void)
+{
+ cout << endl
+ << " mgrep (Martins grep or Multi line grep) is an alternative to grep. " << endl
+ << " The purpose is the same as grep in that it searches files " << endl
+ << " looking for a supplied string. The difference is in the output, " << endl
+ << " aswell as showing the line that contains the string, it also " << endl
+ << " shows the lines around the found line." << endl;
+
+ cout << endl
+ << " When reading from stdin, mgrep works a little differently to grep." << endl
+ << " grep will scan the data on stdin looking for the search string." << endl
+ << " mgrep assumes it is being passed file names, therefore it attempts " << endl
+ << " to open the files and search the contents. " << endl;
+
+ cout << endl
+ << " Please note that mgrep is slower than grep, this is because it " << endl
+ << " performs two passes over the files being searched. " << endl;
+
+ cout << endl
+ << "Syntax:" << endl << endl;
+
+ // cout << " mgrep [ -d -h -l n -b n -a n -s] string [filenames]" << endl;
+ cout << " mgrep [ -d -h -l n -b n -a n ] string [filenames]" << endl;
+ cout << "" << endl;
+ cout << " -h --------- Display this help." << endl;
+ cout << " -d --------- Basic diagnostic information is printed." << endl;
+ cout << " -i --------- Case insensitive search." << endl;
+ cout << " -n --------- No line numbering required." << endl;
+ cout << " -l n ------- Number of lines to show either side of the found line." << endl;
+ cout << " Default is 2." << endl;
+ cout << " -b n ------- Number of lines to show before the found line." << endl;
+ cout << " Default is 2." << endl;
+ cout << " -a n ------- Number of lines to show after the found line." << endl;
+ cout << " Default is 2." << endl;
+ cout << " -s --------- Look for the list of files on STDIN." << endl;
+ cout << " string ----- The string to search for." << endl;
+ cout << " filenames -- List of files to search." << endl << endl;
+}
+
+ // .......................................................................
+
+void Debug(char *Message)
+{
+ if ( DEBUG )
+ {
+ cout << "Debug: " << Message << endl;
+ }
+}
+
+//
+// Read the command line and act on its contents.
+//
+
+void ProcessTheCommandLine(
+ int Argc,
+ char **Argv)
+{
+ grep File;
+
+ int Flag = 'x';
+ int LookAtStdin = 0;
+ int FirstFile = 1;
+ int DiagnosticRequired = 0;
+
+ Debug("ProcessTheCommandLine");
+
+ // Process the command line.
+
+ for ( int Inc = 1; Inc < Argc; Inc++ )
+ {
+ // Have we got a flag?
+
+ if ( *(Argv[Inc]) == '-' )
+ {
+ // Yes.
+
+ Flag = *((Argv[Inc])+1);
+
+ switch ( Flag )
+ {
+ case 'd': // Diagnostics requested
+ DiagnosticRequired = 1;
+ break;
+
+ case 'h': // Help requested
+ Help();
+ exit(0);
+ break;
+
+ case 'i': // Case insensitive search
+ File.CaseInsensitive();
+ break;
+
+ case 'l': // Number of lines to show either side of the found line.
+ Inc++;
+ File.SetLines(atoi(Argv[Inc]));
+ break;
+
+ case 'n':
+ File.NoLineNumbers();
+ break;
+
+ case 'b':
+ Inc++;
+ File.SetLinesBefore(atoi(Argv[Inc]));
+ break;
+
+ case 'a':
+ Inc++;
+ File.SetLinesAfter(atoi(Argv[Inc]));
+ break;
+
+ case 's':
+ LookAtStdin = 1;
+
+ default:
+ cout << Argv[Inc] << " is an invalid flag" << endl;
+ }
+ }
+ else
+ {
+ // This is not a flag, it has to be
+ // the search string or a file name.
+
+ if ( FirstFile )
+ {
+ // Assume the first word following
+ // the flags is the search string.
+
+ File.PutSearchString(Argv[Inc]);
+
+ if ( DiagnosticRequired )
+ {
+ File.Diagnostic();
+ }
+
+ FirstFile = 0;
+ }
+ else
+ {
+ File.Name(Argv[Inc]);
+
+ // ... If the file exists,
+ // ... find and display the lines that contain
+ // ... the search string.
+
+ if ( !File.Exists() )
+ {
+ // cout << "File " << Argv[Inc] << " not found. " << endl;
+ }
+ else
+ {
+ int Found = 0;
+
+ Debug("File Found");
+
+ Found = File.ScanFile();
+
+ // Only proceed with this file if we found matching records.
+
+ if (Found > 0)
+ {
+ File.BuildMatrix();
+ File.ProcessFile();
+ }
+ File.Reset();
+ }
+ }
+ }
+ }
+
+ // Should we scan stdin for file names?
+ // This is a bodge because I cant figure out how to do a non blocking
+ // read on sdtin.
+
+ if (LookAtStdin)
+ {
+ // Yes.
+
+ char FileName[256];
+
+ // check we have a search string before looking in STDIN for filenames.
+
+ if (FirstFile)
+ {
+ cout << __FILE__ << ": Search string not Supplied. " << endl;
+ Help();
+ return;
+ }
+
+ // Disable buffering on stdin. This mean that stdin can be
+ // read without special cmd line flags and fgets does not
+ // lock up the program.
+
+ char Buffer[BUFSIZ];
+
+ // setvbuf(stdin, Buffer);
+
+ // Now check STDIN for file names.
+
+ while (fgets(FileName, 256, stdin))
+ {
+ FileName[strlen(FileName)-1] = '\0';
+ // cout << "stdin loop" << FileName << endl;
+ File.Name(FileName);
+
+ // ... If the file exists,
+ // ... find and display the lines that contain
+ // ... the search string.
+
+ if ( !File.Exists() )
+ {
+ // cout << "File " << FileName << " not found. " << endl;
+ }
+ else
+ {
+ int Found = 0;
+
+ Debug("File Found");
+
+ Found = File.ScanFile();
+
+ // Only proceed with this file if we found matching records.
+
+ if (Found > 0)
+ {
+ File.BuildMatrix();
+ File.ProcessFile();
+ }
+ File.Reset();
+ }
+ }
+ }
+}
+
generated by cgit v1.2.3-54-g00ecf (git 2.39.0) at 2024-04-23 19:28:25 +0000