kurt@pyuxhh.UUCP (K A Gluck) (09/09/85)
rellik gub
# Program to super reverse input
#
# this program will completly reverse its input.
# (with one exception - the output will have an extra line feed
# at its beginning, and the final trainling line feed will be deleted)
# for example, the folowing was a copy of the previous run through
# this program
#
#-------------------------------------------------------------------------
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# .tupni sti esrever yltelpmoc lliw margorp siht
#
# tupni esrever repus ot margorP
#
#-------------------------------------------------------------------------
# This is a shell archive. Remove anything before this line, then
# unpack it by saving it in a file and typing "sh file". (Files
# unpacked will be owned by you and have default permissions.)
#
# This archive contains:
# reverse.c reverse.man
echo x - reverse.c
cat > "reverse.c" << '//E*O*F reverse.c//'
#include <stdio.h>
#include <fcntl.h>
#define strlen 256
main(argc,argv) /* rev- lists file. */
/* argc - number of args*/
/* argv - pointer to array of char strings of args*/
int argc;
char *argv[];
{
int fp, open(), creat() , strcmp() ;
char template[30], *mktemp() , *strcpy() ;
char *tmp;
char *tmpname() ;
long pos;
int n;
if( argc == 1 ) /* no args - halt */
{ printf("rev- no argument given\n");
printf("usage- rev file1 [{filen}]\n");
printf(" alt: rev - reads from stdin (pipes etc...) \n");
exit(1); }
else
while( --argc > 0 )
if( (*++argv)[0] == '-' )
{
if( ( fp = open(( tmp = ( mktemp("/tmp/revXXXXXX\0")) ),O_RDWR | O_CREAT , 0755)) == -1 )
{ printf("rev- cant open %s <<<<\n",*template);
} else {
filecopy(0,fp);
filerev(fp) ;
close(fp);
unlink(tmp);
}
} else {
if (( fp = open(*argv,0)) == -1 ) {
printf("rev- cant open %s ###################\n",*argv);
} else {
filerev(fp) ;
close(fp);
}
}
}
filecopy(fpi,fpo) /* list a file */
int fpi , fpo; /* the file */
{ char c ;
while ( ( read(fpi,&c,1) ) > 0 )
write(fpo,&c,1) ;
}
filerev(fp) /* list a file */
int fp; /* the file */
{ char c ;
long p ;
int flag;
long lseek() ;
int whence;
p=0L ;
whence=2;
flag=1;
while ( ( lseek(fp,p,whence ) ) != -1L ) {
p=0L-2L;
whence=1;
read(fp,&c,1) ;
if( flag==0 ) write(1,&c,1) ;
flag=0;
}
printf("\n");
}
//E*O*F reverse.c//
echo x - reverse.man
cat > "reverse.man" << '//E*O*F reverse.man//'
.tr ~
.de Na
.br
\\$1
..
.de Ex
.IP "" 5
.B \\$1 \\$2 \$3 \\$4 \\$5 \\$6 \\$7 \\$8 \\$9
.P
..
.de Es
.IP "\\$1" 5
.B \\$2 \\$3 \\$4 \\$5 \\$6 \\$7 \\$8 \\$9
..
.de Ee
.br
.B \\$1 \\$2 \\$3 \\$4 \\$5 \\$6 \\$7 \\$8 \\$9
..
.de Ez
.P
..
.tr ~
.TH reverse lman "Pics System Test"
.SH NAME
reverse - c program to reverse files.
.SH SYNOPSIS
.Na "reverse files"
.SH DESCRIPTION
.B reverse
is a filter to reverse files.
It is used in a manner similar to cat (see cat(1)).
.B reverse
will process each of its arguments in turn, reading the files backwards.
If any file has
.B -
for its name,
.B reverse
will create a temporary file, read standard input into that temporary file
and then reverse the temporary file.
.SH EXAMPLES
.Es "To reverse input from terminal" reverse -
.Ez
.Es "To create a confusing listing" ps -ef |reverse -
.Ez
.Es "To reverse the date" date |reverse -
.Ez
.Es "To reverse a file" who >file
.Ee reverse file
.Ez
.SH "SEE ALSO"
cat(1)
.SH AUTHOR
Kurt Gluck, SPL 1c273a x2023
//E*O*F reverse.man//
exit 0
--
Kurt Gluck (201)-561-7100 x2023
SPL 1c273a ihnp4!rruxg!kurt
Bell Communications Research Inc ihnp4!pyuxhh!kurt
50 Cragwood Road
South Plainfield, NJ 07080