Брайан Керниган - UNIX — универсальная среда программирования

progname = argv[0];

if ((p=getenv("PAGESIZE")) != NULL)

pagesize = atoi(p);

if (argc > 1 && argv[1][0] == '-') {

pagesize = atoi(&argv[1][1]);

argc--;

argv++;

}

if (argc == 1)

print(stdin, pagesize);

else

for (i = 1; i < argc; i++)

switch (spname(argv[i], buf)) {

case -1: /* no match possible */

fp = efopen(argv[i], "r");

break;

case 1: /* corrected */

fprintf (stderr, "\"%s\"? ", buf);

if (ttyin() == 'n')

break;

argv[i] = buf;

/* fall through... */

case 0: /* exact match */

fp = efopen(argv[i], "r");

print(fp, pagesize);

fclose(fp);

}

exit(0);

}

print(fp, pagesize) /* print fp in pagesize chunks */

FILE *fp;

int pagesize;

{

static int lines = 0; /* number of lines so far */

char buf[BUFSIZ];

while (fgets(buf, sizeof buf, fp) != NULL)

if (++lines < pagesize) fputs(buf, stdout);

else {

buf[strlen(buf)-1] = '\0';

fputs(buf, stdout);

fflush(stdout);

ttyin();

lines = 0;

}

}

#include "ttyin2.c"

#include "efopen.c"

#include "spname.c"

# pick: select arguments

PATH=/bin:/usr/bin

for i # for each argument

do

echo -n "$i? " >/dev/tty

read response

case $response in

y*) echo $i ;;

q*) break

esac

done

/* pick: offer choice on each argument */

#include

char *progname; /* program name for error message */

main(argc, argv)

int argc;

char *argv[];

{

int i;

char buf[BUFSIZ];

progname = argv[0];

if (argc == 2 && strcmp(argv[1], "-") == 0) /* pick - */

while (fgets(buf, sizeof buf, stdin) != NULL) {

buf[strlen(buf)-1] = '\0'; /* drop newline */

pick(buf);

}

for (i = 1; i < argc; i++)

pick(argv[i]);

exit(0);

}

pick(s) /* offer choice of s */

char *s;

{

fprintf(stderr, "%s? ", s);

if (ttyin() == 'y')

printf("%s\n", s);

}

#include "ttyin2.c"

#include "efopen.c"

# prpages: compute number of pages that pr will print

wc $* |

awk '!/ total$/ { n += int(($1+55) / 56) }

END { print n }'

# put: install file into history

PATH=/bin:/usr/bin

case $# in

1) HIST=$1.H ;;

*) echo 'Usage: put file' 1>&2; exit 1 ;;

esac

if test ! -r $1

then

echo "put: can't open $1" 1>&2

exit 1

fi

trap 'rm -f /tmp/put.[ab]$$; exit 1 12 15

echo -n 'Summary: '

read Summary

if get -o /tmp/put.a$$ $1 # previous version

then # merge pieces

cp $1 /tmp/put.b$$ # current version

echo `getname` `date` $Summary" >>/tmp/put.b$$

diff -e $1 /tmp/put.a$$ >>/tmp/put.b$$ # latest diffs

sed -n '/^@@@/,$р' <$HIST >>/tmp/put.b$$ # old diffs

overwrite $HIST cat /tmp/put.b$$ # put it back

else # make a new one

echo "put: creating $HIST"

cp $1 $HIST

echo "@@@ `getname` `date` $Summary" >>$HIST

fi

rm -f /tmp/put.[ab]$$

/* readslow: keep reading, waiting for more */

#define SIZE 512 /* arbitrary */

main() {

char buf[SIZE];

int n;

for (;;) {

while ((n = read(0, buf, sizeof buf)) > 0)

write(1, buf, n);

sleep(10);

}

}

# replace: replace str1 in files with str2, in place

PATH=/bin:/usr/bin

case $# in

0|1|2) echo 'Usage: replace str1 str2 files' 1>&2; exit 1

esac

left="$1"; right="$2"; shift; shift

for i

do

overwrite $i sed "s@$left@$right@g" $i

done

#include

#include

#include

extern int errno;

main() {

int с, n;

char buf[100];

int onintr();

signal(SIGINT, onintr);

for (;;) {

n = read(0, buf, 100);

if (n > 0)

printf(buf);

else {

if (errno == EINTR) {

errno = 0;

printf("interrupt side %d\n", n);

} else {

printf("true end of file %d\n", n);

}

}

}

}

onintr() {

signal(SIGINT, onintr);

printf("interrupt\n");

}

/* spname: return correctly spelled filename */

/*

* spname(oldname, newname) char *oldname, *newname;

* returns -1 if no reasonable match to oldname,

* 0 if exact match,

* 1 if corrected.

* stores corrected name in newname.

*/

#include

#include

spname(oldname, newname)

char *oldname, *newname;

{

char *p, guess[DIRSIZ+1], best[DIRSIZ+1];

char *new = newname, *old = oldname;

for (;;) {

while (*old == '/') /* skip slashes */

*new++ = *old++;

*new = '\0';

if (*old == '\0') /* exact or corrected */

return strcmp(oldname, newname) != 0;

p = guess; /* copy next component into guess */

for ( ; *old != '/' && *old != '\0'; old++)

if (p < guess+DIRSIZ)

*p++ = *old;

*p = '\0';

if (mindist(newname, guess, best) >= 3)

return -1; /* hopeless */

for (p = best; *new = *p++; ) /* add to end */

new++; /* of newname */

}

}

mindist(dir, guess, best) /* search dir for guess */

char *dir, *guess, *best;

{

/* set best, return distance 0..3 */

int d, nd, fd;

struct {

ino_t ino;

char name[DIRSIZ+1]; /* 1 more than in dir.h */

} nbuf;

nbuf.name[DIRSIZ] = '\0'; /* +1 for terminal '\0' */

if (dir[0] == '\0') /* current directory */

dir = ".";

d = 3; /* minimum distance */

if ((fd=open(dir, 0)) == -1)

return d;

while (read(fd, (char*)&nbuf, sizeof(struct direct)) > 0)

if (nbuf.ino) {

nd = spdist(nbuf.name, guess);

if (nd <= d && nd != 3) {

strcpy(best, nbuf.name);

d = nd;

if (d == 0) /* exact match */

break;

}

}

close(fd);

return d;

}

/* spdist: return distance between two names */

/*

* very rough spelling metric:

* 0 if the strings are identical

* 1 if two chars are transposed

* 2 if one char wrong, added or deleted

* 3 otherwise

*/

#define EQ(s,t) (strcmp(s,t) == 0)

spdist(s, t)

char *s, *t;

{

while (*s++ == *t)

if (*t++ == '\0')

return 0; /* exact match */

if (*--s) {

if (*t) {

if (s[1] && t[1] && *s == t[1] && *t == s[1] && EQ(s+2, t+2))

return 1; /* transposition */

if (EQ(s+1, t+1))

return 2; /* 1 char mismatch */

}

if (EQ(s+1, t))

return 2; /* extra character */

}

if (*t && EQ(s, t+1))

return 2; /* missing character */

return 3;

}

strindex(s, t) /* return index of t in s, -1 if none */

char *s, *t;

{

int i, n;

n = strlen(t);

for (i = 0; s[i] != '\0'; i++)

if (strncmp(s+i, t, n) == 0)

return i;

return -1;

}

/* sv: save new files */

#include

#include

#include

#include

char *progname;

main(argc, argv)

int argc;

char *argv[];

{

int i;

struct stat stbuf;

char *dir = argv[argc-1];

progname = argv[0];

if (argc <= 2)

error ("Usage: %s files... dir", progname);

if (stat(dir, festbuf) == -1)

error("can't access directory %s", dir);

if ((stbuf.st_mode & S_IFMT) != S_IFDIR)

error("%s is not a directory", dir);