Читаем без скачивания UNIX — универсальная среда программирования - Брайан Керниган
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Интервал:
Закладка:
PATH=/bin:/usr/bin
VERSION=0
while test "$1" != ""
do
case "$1" in
-i) INPUT=$2; shift ;;
-o) OUTPUT=$2; shift ;;
-[0-9]) VERSION=$1 ;;
-*) echo "get: Unknown argument $i" 1>&2; exit 1 ;;
*) case "$OUTPUT" in
"") OUTPUT=$1 ;;
*) INPUT=$1.H ;;
esac
esac
shift
done
OUTPUT=${OUTPUT?"Usage: get [-o outfile] [-i file.H] file"}
INPUT=${INPUT-$OUTPUT.H}
test -r $INPUT || { echo "get: no file $INPUT" 1>&2; exit 1; }
trap 'rm -f /tmp/get.[ab]$$; exit 1' 1 2 15
# split into current version and editing commands
sed <$INPUT -n '1,/^@@@/w /tmp/get.a'$$'
/^@@@/,$w /tmp/get.b'$$
# perform the edits
awk </tmp/get.b$$ '
/^@@@/ { count++ }
!/^@@@/ && count > 0 && count <= - '$VERSION'
END { print "$d"; print "w", "'$OUTPUT'" }
' | ed - /tmp/get.a$$
rm -f /tmp/get.[ab]$$
3.8.25 get.с
get(fd, pos, buf, n) /* read n bytes from position pos */
int fd, n;
long pos;
char *buf;
{
if (lseek(fd, pos, 0) == -1) /* get to pos */
return -1;
return read(fd, buf, n);
}
3.8.26 getname
who am i | sed 's/ .*//'
3.8.27 idiff.c
/* idiff: interactive diff */
#include <stdio.h>
#include <ctype.h>
char *progname;
#define HUGE 10000 /* large number of lines */
main(argc, argv)
int argc;
char *argv[];
{
FILE *fin, *fout, *f1, *f2, *efopen();
char buf[BUFSIZ], *mktemp();
char *diffout = "idiff.XXXXXX";
progname = argv[0];
if (argc != 3) {
fprintf(stderr, "Usage: idiff file1 file2n");
exit(1);
}
f1 = efopen(argv[1], "r");
f2 = efopen(argv[2], "r");
fout = efopen("idiff.out", "w");
mktemp(diffout);
sprintf(buf, "diff %s %s >%s", argv[1], argv[2], diffout);
system(buf);
fin = efopen(diffout, "r");
idiff(f1, f2, fin, fout); unlink(diffout);
printf("%s output in file idiff.outn", progname);
exit(0);
}
idiff(f1, f2, fin, fout) /* process diffs */
FILE *f1, *f2, *fin, *fout;
{
char *tempfile = "idiff.XXXXXX";
char buf[BUFSIZ], buf2[BUFSIZ], *mktemp();
FILE *ft, *efopen();
int cmd, n, from1, to1, from2, to2, nf1, nf2;
mktemp(tempfile);
nf1 = nf2 = 0;
while (fgets(buf, sizeof buf, fin) != NULL) {
parse(buf, &from1, &to1, &cmd, &from2, &to2);
n = to1-from1 + to2-from2 + 1; /* #lines from diff */
if (cmd == 'c')
n += 2;
else if (cmd == 'a')
from1++;
else if (cmd == 'd')
from2++;
printf("%s", buf);
while (n-- > 0) {
fgets(buf, sizeof buf, fin);
printf("%s", buf);
}
do {
printf("? ");
fflush(stdout);
fgets(buf, sizeof buf, stdin);
switch (buf[0]) {
case '>':
nskip(f1, to1-nf1);
ncopy(f2, to2-nf2, fout);
break;
case '<':
nskip(f2, to2-nf2);
ncopy(f1, to1-nf1, fout);
break;
case 'e':
ncopy(f1, from1-1-nf1, fout);
nskip(f2, from2-1-nf2);
ft = efopen(tempfile, "w");
ncopy(f1, to1+1-from1, ft);
fprintf(ft, "--- n");
ncopy(f2, to2+1-from2, ft);
fclose(ft);
sprintf(buf2, "ed %s", tempfile);
system(buf2);
ft = efopen(tempfile, "r");
ncopy(ft, HUGE, fout);
fclose(ft);
break;
case '!':
system(buf+1);
printf("!n");
break;
default:
printf("< or > or e or !n");
break;
}
} while (buf[0]!= '<' && buf[0]!= '>' && buf[0]! = 'e');
nf1 = to1;
nf2 = to2;
}
ncopy(f1, HUGE, fout); /* can fail on very long files */
unlink(tempfile);
}
parse(s, pfrom1, pto1, pcmd, pfrom2, pto2)
char *s;
int *pcmd, *pfrom1, *pto1, *pfrom2, *pto2;
{
#define a2i(p) while (isdigit(*s))
p = 10*(p) + *s++ - '0'
*pfrom1 = *pto1 = *pfrom2 = *pto2 = 0;
a2i(*pfrom1);
if (*s == ',') {
s++;
a2i(*pto1);
} else
*pto1 = *pfrom1;
*pcmd = *s++;
a2i(*pfrom2);
if (*s == ',') {
s++;
a2i(*pto2);
} else
*pto2 = *pfrom2;
}
nskip(fin, n) /* skip n lines of file fin */
FILE *fin;
{
char buf[BUFSIZ];
while (n-- > 0)
fgets(buf, sizeof buf, fin);
}
ncopy(fin, n, fout) /* copy n lines from fin to fout */
FILE *fin, *fout;
{
char buf[BUFSIZ];
while (n-- > 0) {
if (fgets(buf, sizeof buf, fin) == NULL)
return;
fputs(buf, fout);
}
}
#include "efopen.c"
3.8.28 makefile
files: files.o files1.o directory.o
cc files.o files1.o directory.o -o files
p0: p0.c ttyin0.c
cc p0.c ttyin0.c
clean:
rm -f *.o a.out
3.8.29 newer
# newer f: list files newer than f
ls -t | sed '/^'$1'$/q'
3.8.30 news1
# news: print news files, version 1
HOME=. # debugging only
cd . # place holder for /usr/news
for i in `ls -t * $HOME/.news_time`
do
case $i in
*/.news_time) break ;;
*) echo news: $i
esac
done
touch $HOME/.news_time
3.8.31 news2
# news: print news files, version 2
HOME=. # debugging only
cd . # place holder for /usr/news
IFS='
' # just a newline
for i in `ls -t * $HOME/.news_time 2>&1`
do
case $i in
*' not found') ;;
*/.news_time) break ;;
*) echo news: $i ;;
esac
done
touch $HOME/.news_time
3.8.32 news3
# news: print news files, final version
PATH=/bin:/usr/bin
IFS='
' # just a newline
cd /usr/news
for i in `ls -t * $HOME/.news_time 2>&1`
do
IFS=' '
case $i in
*' not found') ;;
*/.news_time) break ;;
*) set X`ls -l $i`
echo "
$i: ($3) $5 $6 $7
"
cat $i
esac
done
touch $HOME/.news_time
3.8.33 nohup
trap "" 1 15
if test -t 2>&1
then
echo "Sending output to 'nohup.out'"
exec nice -5 $* >>nohup.out 2>&1
else
exec nice -5 $* 2>&1
fi
3.8.34 older
# older f: list files older than f
ls -tr | sed '/^'$!'$/q'
3.8.35 overwrite1
# overwrite: copy standard input to output after EOF
# version 1. BUG here
PATH=/bin:/usr/bin
case $# in
1) ;;
*) echo 'Usage: overwrite file' 1>&2; exit 2
esac
new=/tmp/overwr.$$
trap 'rm -f $new; exit 1' 1 2 15
cat >$new # collect the input
cp $new $1 # overwrite the input file
rm -f $new
3.8.36 overwrite2
# overwrite: copy standard input to output after EOF
# version 2. BUG here too
PATH=/bin:/usr/bin
case $# in
1) ;;
*) echo 'Usage: overwrite file' 1>&2; exit 2
esac
new=/tmp/overwr1.$$
old=/tmp/overwr2.$$
trap 'rm -f $new $old; exit 1' 1 2 15
cat >$new # collect the input
cp $1 $old # save original file
trap '' 1 2 15 # we are committed; ignore signals
cp $new $1 # overwrite the input file
rm -f $new $old
3.8.37 overwrite3
# overwrite: copy standard input to output after EOF
# final version
opath=$PATH
PATH=/bin:/usr/bin
case $# in
0|1) echo 'Usage: overwrite file cmd [args]' 1>&2; exit 2
esac
file=$1; shift
new=/tmp/overwr1.$$; old=/tmp/overwr2.$$
trap 'rm -f $new $old; exit 1' 1 2 15 # clean up files
if PATH=$opath >$new # collect input
then
cp $file $old # save original file
trap '' 1 2 15 # we are committed; ignore signals
cp $new $file
else
echo "overwrite: $1 failed, $file unchanged" 1>&2
exit 1
fi
rm -f $new $old
3.8.38 p1.c
/* p: print input in chunks (version 1) */
#include <stdio.h>
