segedy@gsg.UUCP (Catherine Segedy) (12/08/88)
Posting-number: Volume 5, Issue 76
Submitted-by: "Catherine Segedy" <segedy@gsg.UUCP>
Archive-name: uns
Due to all the noise recently about the dangers of shell scripts for
unpacking maps, I recently posted to comp.unix.wizards, news.sysadmin,
and news.admin, describing the following program. I would have just posted
it, but I was delayed a few days for something. Anyway, here it is. I hope
this is helpful.
cathy segedy, GSG
decvax!gsg!segedy
harvard!gsg!segedy
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
#! /bin/sh
# This file was wrapped with "dummyshar". "sh" this file to extract.
# Contents: uns.c
echo extracting 'uns.c'
if test -f 'uns.c' -a -z "$1"; then echo Not overwriting 'uns.c'; else
sed 's/^X//' << \EOF > 'uns.c'
X/* Copyright 1988 by GSG, Salem, NH -- permission is given to copy this and
X use it as long as it is not sold or used commercially, and as long as
X this copyright is included with it.
X
X Author: Cathy Segedy
X send comments, etc. to: decvax!gsg!segedy or
X harvard!gsg!segedy
X date: Dec. 7, 1988
Xno guarantees or warranties are made, either implicitly or explicitly about the
Xcorrectness of this program, and it is presented as is, and use at your own
Xrisk.
X
Xto compile this program, (uns.c):
X cc -o uns uns.c
Xto use this program: (I use it this way)
X uns mapfilename >> some_output_file
Xthis should produce the mapfile. The output file should contain
X a message about the opening of the input file
X a message about removing end_of_line
X a message about the open of the mapfile
X all the lines which come after the SHAR_EOF
X a message about closing files
Xthis program doesn't get rid of any shell commands which someone might try to
Xslip in, but since it is not a shell script, they shouldn't get executed.
XPlus, the output file will be full of garbage if there was stuff tacked on
Xafter the SHAR_EOF.
XSomeone might wish to shorten MAXLIN (do map files have a line limit?)
X*/
X
X#include <stdio.h>
X
X#define MAXLIN 256
X
Xmain(argc,argv)
Xint argc;
Xchar *argv[];
X{
X FILE *fp, *fp2;
X char buffer[MAXLIN];
X int at_beginning, at_end;
X char filename[20], file2[20];
X
X at_beginning = 0;
X at_end = 0;
X
X if(argc != 2){
X printf("bad arguements\n");
X exit(1);
X }
X
X strcpy(filename,argv[1]);
X
X printf("opening file {%s}\n",filename);
X if((fp = fopen(filename, "r")) == NULL) {
X printf("can not open file {%s}\n",filename);
X exit(1);
X }
X else{
X while( (!at_beginning) && (fgets(buffer,MAXLIN,fp) != NULL) ){
X if(strncmp(buffer,"cat << 'SHAR_EOF' > ",20) == 0){
X at_beginning = 1;
X }
X }
X if(!at_beginning){
X printf("couldn't find beginning, exiting\n");
X fclose(fp);
X exit(1);
X }
X printf("removing end-of-line while copying\n");
X strncpy(file2,&buffer[20],(strlen(&buffer[20]) - 1));
X printf("opening file {%s}\n",file2);
X if((fp2 = fopen(file2, "w")) == NULL) {
X printf("can not open file {%s}\n",file2);
X exit(1);
X }
X
X while( (!at_end) && (fgets(buffer,MAXLIN,fp) != NULL) ){
X if(strncmp(buffer,"SHAR_EOF",8) != 0){
X fprintf(fp2,"%s",buffer);
X }
X else{
X at_end = 1;
X }
X }
X }
X while( fgets(buffer,MAXLIN,fp) != NULL){
X printf("%s",buffer);
X }
X
X printf("closing files\n");
X fclose(fp);
X fclose(fp2);
X}
EOF
chars=`wc -c < 'uns.c'`
if test $chars != 2579; then echo 'uns.c' is $chars characters, should be 2579 characters!; fi
fi
exit 0