OS/2 Shareware BBS: 11 Util/11-Util.zip/dhg_106a.zip/DHG_LRG.HLP

OS/2 Help File | 1999-02-26 | 16KB | 421 lines

ΓòÉΓòÉΓòÉ 1. DH-Grep-PM Introduction ΓòÉΓòÉΓòÉ

General information about DH-Grep-PM

Grep stands for "Get Regular Expression and Print" and is a text searching tool
that was first developed for unix systems and has been ported to most operating
systems.

This PM version of grep is designed as a user friendly application.  It is
designed for a multitasking environment and the search takes place on a
separate thread to minimize the time that the wait icon is displayed. It will
also run in a low priority idle mode to further reduce the impact the search
has on the other active programs.

The often cryptic command line options have been replaced with easy to use
selections on the OS/2 menu bar. The output of the search is sent to a PM
window and the user has easy access to all of the information that was found by
the program.

To reduce the overhead, the results are buffered until the search is completed
and then written to the results window.  To indicate that the search is still
active, the small icon at the left of the title bar will change color as an
activity indicator. The color change depends on the search results, so it does
not change at a fixed rate.

This program will try to search binary files as well as text files, but it
still tries to read "lines" from the binary file.  The program reads from the
file until a new-line is found or 4096 characters have been read.

If a new-line is not found and the program reads in 4096 characters there is a
very good chance that a word will be split.  If that word is what you are
searching for, the search will fail.

Binary files can and often do contain null characters. The C/C++ string
handling functions all use a null character as a string terminator and the
"line" will be truncated at the first null character by those functions.  This
means that the program may miss finding the search pattern in a binary file.

I have added an option to replace null characters with spaces, but using that
option will increase the search time. This option may be useful when doing a
search in word processor files.  See BINARY Flag

This version of grep does not support the full set of "regular expressions"
that most of the command line versions of grep support.  It does support two
wild-card characters.  The '*' character represents multiple characters and the
character '?' represents one character. Thus a search pattern of "h*e"  would
match both "house" and "horse". A search pattern of "ho?se" would also match
both words.


ΓòÉΓòÉΓòÉ 1.1. Binary Files ΓòÉΓòÉΓòÉ

This program will try to search binary files as well as text files, but it
still tries to read "lines" from the binary file.  The program reads from the
file until a new-line is found or 4096 characters have been read.

If a new-line is not found and the program reads in 4096 characters there is a
very good chance that a word will be split.  If that word is what you are
searching for, the search will fail.

Binary files can and often do contain null characters. The C/C++ string
handling functions all use a null character as a string terminator and the
"line" will be truncated at the first null character by those functions.  This
means that the program may miss finding the search pattern in a binary file.

I have added an option to replace null characters with spaces, but using that
option will increase the search time. This option may be useful when doing a
search in word processor files.  See BINARY Flag


ΓòÉΓòÉΓòÉ 1.2. Regular Expressions ΓòÉΓòÉΓòÉ

This version of grep does not support the full set of "regular expressions"
that most of the command line versions of grep support.  It does support two
wild-card characters.  The '*' character represents multiple characters and the
character '?' represents one character. Thus a search pattern of "h*e"  would
match both "house" and "horse". A search pattern of "ho?se" would also match
both words.


ΓòÉΓòÉΓòÉ 1.3. File ΓòÉΓòÉΓòÉ

This menu selection opens a pull-down menu that contains selections to save,
reload, or print the results of the search. The external editor is also on this
menu.


ΓòÉΓòÉΓòÉ 1.3.1. Save As ΓòÉΓòÉΓòÉ

The Save As selection opens a file dialog box that allows the user to enter a
file name to use for saving the search results. If the user enters the name of
an existing file, the utility will warn the user and ask for verification
before writing the file.


ΓòÉΓòÉΓòÉ 1.3.2. Load File ΓòÉΓòÉΓòÉ

The Load File selection opens a file dialog box that allows the user to select
a file to load into the results window.


ΓòÉΓòÉΓòÉ 1.3.3. Print On Default Printer ΓòÉΓòÉΓòÉ

The Print On Default Printer selection sends the contents of the results window
to the default system printer. This is a raw dump of the results window to the
default system printer and no attempt to format the text.


ΓòÉΓòÉΓòÉ 1.3.4. Load Marked File In External Editor ΓòÉΓòÉΓòÉ

To use the external editor option, you must create a CMD file named
EDIT_CMD.CMD that calls the editor you wish to use.  A minimal CMD file to use
the OS/2 system editor E would contain the following line.

e %1

The CMD file should be located in the working directory.

To use the external editor, the cursor must be on a line that contains the name
of a file that was found during the search. After the cursor is on the line,
either an ALT+W key press or a Right Mouse Button double click will launch the
CMD file. The cusror can be moved to a specific line by a Left Mouse Button
click.

Note:  The RMB double click will not move the cursor to the desired line.


ΓòÉΓòÉΓòÉ 1.4. Display ΓòÉΓòÉΓòÉ

This menu selection opens a pull-down menu that contains selections that affect
how the results are displayed after the search has been completed.


ΓòÉΓòÉΓòÉ 1.4.1. Font ΓòÉΓòÉΓòÉ

The Font selection opens a standard OS/2 Font dialog box that lets the user
select a new font or change the font size for the displayed results.  This will
allow the selection of any of the installed fonts. This option only changes the
font in the main window.

To change the font for the menubar or the information area below the main
window, use the OS/2 font palette and drag and drop a new font on either area.
The font selections are only saved when 'Save Settings' is selected.

Note:  For the main window, font drag and drop does not always work correctly.
The displayed font will be correct, but the wrong font size may be saved.


ΓòÉΓòÉΓòÉ 1.4.2. Word Wrap ΓòÉΓòÉΓòÉ

The Word Wrap selection enables or disables the word wrap feature of the
results window.

Note:  The Word Wrap is a software word wrap and it does not insert hard
       carriage return - line feed  pairs.


ΓòÉΓòÉΓòÉ 1.4.3. Do not clear past results ΓòÉΓòÉΓòÉ

This selection disables the clearing of the results window when a new search is
started.  It is useful if the user wishes to save the search results from
several related searches.


ΓòÉΓòÉΓòÉ 1.4.4. Reset to default colors ΓòÉΓòÉΓòÉ

The 'Reset to default colors' option restores the system default background and
foreground colors.  To change the colors on the menubar, main window, or the
information area use the OS/2 color palette and drag and drop a color
selection.  When 'Save Settings is selected , the color selections are made the
default colors.

Note:  The background and foreground colors of the results window may be set
       via drag and drop from the OS/2 Color Palette. The other colors may also
       be changed, but only the background and foreground colors of the results
       window are saved.


ΓòÉΓòÉΓòÉ 1.4.5. Get file names in display ΓòÉΓòÉΓòÉ

This selection will cause the program to scan all of the results text and
extract the file names and insert them at the top of the results window.  This
provides the user with a list of file names that can be imported into another
document or used by another program.


ΓòÉΓòÉΓòÉ 1.4.6. Edit ΓòÉΓòÉΓòÉ

The results window is an MLE (MultiLine Editor) window and it has the basic
OS/2 editor functions. This selection brings up a submenu with the available
edit functions.


ΓòÉΓòÉΓòÉ 1.4.7. Open Enter Search Parameters Immediately ΓòÉΓòÉΓòÉ

This selection will cause the program to open the 'Enter Search Parameters'
window immediately after the program is loaded.  This is one of the settings
that are saved when the user selects the "Save option settings in program INI
file" menu item.


ΓòÉΓòÉΓòÉ 1.5. Configure Search ΓòÉΓòÉΓòÉ

This menu selection opens a pull-down menu that contains selections to
configure the search and the search parameters.


ΓòÉΓòÉΓòÉ 1.5.1. Case Sensitive Search ΓòÉΓòÉΓòÉ

When this option is checked, the search is case sensitive.  The default is to
ignore case in the search pattern.


ΓòÉΓòÉΓòÉ 1.5.2. Set absolute flag ΓòÉΓòÉΓòÉ

When this option is checked, the search pattern is absolute. The two wild-card
characters are treated as characters and not wild-cards.

Regular Expressions


ΓòÉΓòÉΓòÉ 1.5.3. Search Subdirectories ΓòÉΓòÉΓòÉ

When this option is checked, the program starts the search in the specified
directory and searches in all subdirectories (recursively) for files that match
the file mask. The default is to not search in subdirectories.


ΓòÉΓòÉΓòÉ 1.5.4. Set NOT Flag ΓòÉΓòÉΓòÉ

When this option is checked, the search results will contain all the lines that
do not contain the search pattern. This means that all of the lines in a file
that does not contain the search pattern would be displayed in the results
window.


ΓòÉΓòÉΓòÉ 1.5.5. Set NAME Flag ΓòÉΓòÉΓòÉ

When this option is checked, only the names of files that contain the search
pattern are displayed in the results window.


ΓòÉΓòÉΓòÉ 1.5.6. Show Line Numbers ΓòÉΓòÉΓòÉ

When this option is checked, line numbers are included in the results window.
This makes it easier to find the search pattern when the file is loaded into an
editor.


ΓòÉΓòÉΓòÉ 1.5.7. Use idle time priority for search thread ΓòÉΓòÉΓòÉ

When this option is checked, the priority of the thread that does the searching
is reduced to the lowest priority. This priority only gets processing time when
there is no other work to do.  This option allows the user to do a search in
the background without a significant impact on the other active tasks.


ΓòÉΓòÉΓòÉ 1.5.8. Files newer than Age Mask ΓòÉΓòÉΓòÉ

When this option is checked, only files with dates newer or equal to the Age
Mask value will be evaluated.

File Age


ΓòÉΓòÉΓòÉ 1.5.9. Files older than Age Mask ΓòÉΓòÉΓòÉ

When this option is checked, only files with dates older than the Age Mask
value will be evaluated.  Do not use this option with a Age Mask of 0, it will
just increase the search time.

File Age


ΓòÉΓòÉΓòÉ 1.5.10. Skip known binary files ΓòÉΓòÉΓòÉ

When this option is checked, the utility will skip the following known binary
file types by looking at the file extent.

 .exe, .dll, .lib, .ico, .gif, .jpg

 .zip, .inf, .hlp, .obj, .com, .res

This utility will try to search for the search pattern in any file. If you know
the extent of the files you wish to search, you should use that extent in the
file mask to reduce the number of files that are searched.

If you are not sure of the file extent and you know that you do not need to
search any binary files, then this option should be selected.

Binary Files


ΓòÉΓòÉΓòÉ 1.5.11. Search for files only, no pattern search ΓòÉΓòÉΓòÉ

When this option is checked, the utility will just search for files that match
the file mask and the other search parameters. The contents of the file will
not be checked.


ΓòÉΓòÉΓòÉ 1.5.12. BINARY Flag ΓòÉΓòÉΓòÉ

When this option is checked, the program will replace any null characters that
are read with spaces. The file being searched is not modified, only the data
that is read from the file.

This option is intended for searching word processor files that have embedded
null characters - such as DeScribe.  Using this option will increase the search
time, so it should only be used when needed.

Searches in binary files often fail. Many compilers will compress or condense
text strings and a search will not find the altered text.  Many word processors
also modify text so that addional information about formatting can be stored
with the text.

Binary Files


ΓòÉΓòÉΓòÉ 1.5.13. Enter Search Parameters ΓòÉΓòÉΓòÉ

This selection opens a dialog box that has 4 entry fields.

Search Path

File Mask

Search Pattern

File Age

All the fields except 'File Age' must be filled in or the search cannot be
started.

The 'Search Path' is checked to see if a valid path has been entered when the
user clicks on the 'Ok' or 'Start' buttons.


ΓòÉΓòÉΓòÉ 1.5.13.1. Search Path ΓòÉΓòÉΓòÉ

The search path consists of the Drive letter and the path without the file
name.

For Example:  C:\OS2\APPS\

The ending '\' is not required

The searching of subdirectories is controled by another option setting under
'Configure Search' on the menubar.

Search Subdirectories


ΓòÉΓòÉΓòÉ 1.5.13.2. Browse ΓòÉΓòÉΓòÉ

The Browse button opens a dialog box that will allow the user to select a
search path.  This dialog box is similar to the normal File Dialog box , except
that there is no way to select a file name.  The file names are still displayed
to aid the user in finding the correct directory.

File Mask


ΓòÉΓòÉΓòÉ 1.5.13.3. File Mask ΓòÉΓòÉΓòÉ

The file mask represents the file or files to be searched without any path
information. Wild cards are allowed.

For Example:
*.txt
*.msg
a?bc.txt

Note:  In OS/2  "*" as a search pattern (not "*.*") means search ALL files.


ΓòÉΓòÉΓòÉ 1.5.13.4. Search Pattern ΓòÉΓòÉΓòÉ

The search pattern can contain up to 512 characters. This version of grep does
not support the full set of "regular expressions" that most of the command line
versions of grep support.  It does support two wild-card characters.  The '*'
character represents multiple characters and the character '?' represents one
character. Thus a search pattern of "h*e"  would match both "house" and
"horse". A search pattern of "ho?se" would also match both words.

The use of the wild-card characters depends on the setting of the Set absolute
flag


ΓòÉΓòÉΓòÉ 1.5.13.5. File Age ΓòÉΓòÉΓòÉ

The File Age entry is used when one of the age limit options is used. The
number can be in the range 0 to 999 days.  The lower range of zero is used to
indicate today when the 'newer than' search option is checked.

Files newer than Age Mask

Files older than Age Mask


ΓòÉΓòÉΓòÉ 1.5.14. Save option settings in program INI file ΓòÉΓòÉΓòÉ

When option is selected, the current configuration information, the size and
location of the application window, the background and foreground colors, the
current font and font size are saved in the file named DHGREPPM.INI.


ΓòÉΓòÉΓòÉ 1.6. Start ΓòÉΓòÉΓòÉ

This selection on the menu bar is used to start the search.  The selection is
inactive until the search parameters have been entered and while the search is
in progress.  The 'Start' button on the 'Enter Search Parameters' dialog box
performs the same action as the selection on the menu bar. *


ΓòÉΓòÉΓòÉ 1.7. Stop ΓòÉΓòÉΓòÉ

This selection on the menu bar is used to stop the search.  The selection is
inactive until the search is in progress and becomes inactive when the search
has been completed or stopped.  A dialog box is displayed when 'Stop' is
selected and the user is asked to verify that he wants to stop the search. *