gsar
Section: User Commands (1)
Updated: 14 Aug 1996
Index
Return to Main Contents
NAME
gsar - General Search And Replace utility
SYNOPSIS
gsar [options] [infile(s)] [outfile]
DESCRIPTION
gsar (General Search And Replace) is a utility for searching
for and --- optionally --- replacing strings in both text and
binary files. The search and replace strings can contain all kinds
of characters (0--255), i.e. Ctrl characters and extended ASCII
as well.
The algorithm used is a variation of the Boyer-Moore search
algorithm, modified to search binary files. As a result of
this, gsar is blindingly fast.
Opposed to line oriented search programs (like grep(1)), gsar will
find all matches on a line. Actually, gsar doesn't know anything
about lines at all, all files and strings are treated as binary.
Gsar can search one or several files for a string and report
the occurrences. Gsar can read one file, search for a string,
replace it with some other string, and create a new file
containing the changes. Gsar can perform a search and replace
in multiple files, overwriting the originals. Finally, gsar
can work as a filter, reading from standard input and writing
to standard output.
OPTIONS
All options can be concatenated into one single option
i.e the command: gsar -i -b -l is the same as gsar -ibl
An option which takes an argument must be the last one in the
concatenated option, since the rest of the option is taken as
a possible argument.
Fields enclosed in [] are optional, but mandatory when enclosed in <>.
Options are case sensitive i.e -b is not the same as -B.
If no options are given, gsar just gives a brief help message.
[infile(s)]
Name(s) of input file(s) (wildcards allowed on most Unix shells and
most DOS compilers). If the -F option is used input is taken from
stdin.
[outfile]
Name of output file that is to contain the replacements.
If the -F option is used, transformed output is sent to
stdout.
-s<string>
String to search for in file. Ctrl characters can be entered
by using a `:' in the string followed by the ASCII value of
the character. The value is entered using a `:' followed by
three decimal digits or `:x' followed by two hex numbers.
To enter a colon (:) in the search pattern use `::'.
The string must follow directly after s.
Example:
To search for the string :foo (`o' is 111 decimal, 6F in hex)
use the search options:
-s::foo or -s::fo:111 or -s::fo:x6F
If you want to search for a string with spaces in it,
under MSDOS surround the expression with quotes.
Under Unix, use the mechanisms your shell provides (commonly quotes)
to include space or other special characters.
Example: search for gsar is fast use:
gsar "-sgsar is fast" foobar.txt
The precompiled MSDOS executable in the archive supports response
files. Just put you gsar commands into a file and put a `@' in front
of the filename on the gsar command line.
Example: file foobar.txt contains
-ssupercalifragilisticexpialidocus:
gsar @foobar.txt poppins.txt
If response files are needed, most Unix shells will allow
gsar `cat foobar.txt` poppins.txt
-r[string]
String which is to replace search string in file. Use -r
to delete the search string from the file i.e. replace with
nothing. Ctrl characters can be entered in the same way as
in the search string. If this option is left out, gsar only
performs a search. The string must follow directly after r.
-i
Ignore case difference when comparing strings.
I.e. foobar matches fooBAR.
-B
Just display the search & replace buffers, for test purposes.
-f
If the output file already exists this switch can be used to
force an overwrite of the existing output file.
-o
Search and replace of multiple files, overwrite the input
file(s). For each input file, gsar creates a tempfile
which contains the replacements and copies the tempfile
to the original input file name. If no matches were found,
the input file stays the same. The tempfile is removed.
Example:
gsar -s__ZTC__ -r__TURBOC__ -o foo.c bar.c bat.c
The files foo.c, bar.c & bat.c are
all changed.
-c[n]
Display the context around a match in a textual manner.
Undisplayable characters are displayed as a dot (`.'). n is
optional number of bytes in context. n must follow directly
after c.
-x[n]
Display the context around a match as a hexadecimal dump.
Undisplayable characters are displayed as a dot (`.'). n is
optional number of bytes in context. n must follow directly
after x.
-b
Display the byte offset of the match in hex.
-l
Only list filename and number of matches if any (default).
-h
Suppress display of filename when displaying context or byte offsets.
-du
Convert a DOS ASCII file to UNIX (strips carriage return).
-ud
Convert a UNIX ASCII file to DOS (adds carriage return).
-F
Filter mode, gsar takes it's input from stdin and redirects
eventual output to stdout. All error messages are sent stderr.
-G
Display the GNU General Public Licence.
Examples
Search for two spaces at the end of a line (DOS text) and
replace with just a carriage return overwriting the original
files:
gsar -s:x20:x20:x0d -r:x0d -o foobar.txt *.c
Convert a UNIX text file to DOS format overwriting the original
file:
gsar -ud -o unix.txt
Search for the string WATCOM and replace with __ZTC__ using
gsar as a filter. Output is redirected to a new file:
gsar -sWATCOM -r__ZTC__ -F < foo_w.c > foo_z.c
Display textual context of the string error in the file
gsar.exe disregarding case. With 40 bytes in the context:
gsar -serror -i -c40 gsar.exe
Search for the string gnu in the file fsf and replace it
with wildebeest, creating a new output file africa:
gsar -sgnu -rwildebeest fsf africa
(if the file africa exists, you have to use the -f
option to overwrite it.)
Search for the string error in the file command.com
and display the byte offset of each match:
gsar -serror -b command.com
Limitations
No wildcards or regular expressions allowed in search string.
On MSDOS platforms stdin from a tty is not allowed because
stdin has been turned into binary. MSDOS will not catch the
Ctrl-Z signifying EOF.
Authors
Tormod Tjaberg (coding, design (all bugs are his))
Hans Peter Verne (ideas, demands, testing, UNIX platforms)
If you have any comments, bug reports or whatever, we
can be reached through email at:
tormod@sn.no
hpv@kjemi.uio.no
Index
- NAME
-
- SYNOPSIS
-
- DESCRIPTION
-
- OPTIONS
-
- [infile(s)]
-
- [outfile]
-
- -s<string>
-
- -r[string]
-
- -i
-
- -B
-
- -f
-
- -o
-
- -c[n]
-
- -x[n]
-
- -b
-
- -l
-
- -h
-
- -du
-
- -ud
-
- -F
-
- -G
-
- Examples
-
- Limitations
-
- Authors
-
This document was created by
man2html,
using the manual pages.
Time: 06:21:07 GMT, August 30, 2022