Implement -e support for grep
This commit is contained in:
sin
parent
82bff35228
commit
f526ad099f
9
grep.1
9
grep.1
|
|
@ -4,6 +4,8 @@ grep \- search files for a pattern
|
|||
.SH SYNOPSIS
|
||||
.B grep
|
||||
.RB [ \-Ecilnqv ]
|
||||
.RB [ \-e
|
||||
.I pattern ]
|
||||
.I pattern
|
||||
.RI [ file ...]
|
||||
.SH DESCRIPTION
|
||||
|
|
@ -25,6 +27,13 @@ matches using extended regex.
|
|||
.B \-c
|
||||
prints only a count of matching lines.
|
||||
.TP
|
||||
.B \-e pattern
|
||||
Specify a pattern used during the search of the input: an input
|
||||
line is selected if it matches any of the specified patterns.
|
||||
This option is most useful when multiple -e options are used to
|
||||
specify multiple patterns, or when a pattern begins with a dash
|
||||
(`-').
|
||||
.TP
|
||||
.B \-i
|
||||
matches lines case insensitively.
|
||||
.TP
|
||||
|
|
|
|||
129
grep.c
129
grep.c
|
|
@ -10,19 +10,27 @@
|
|||
|
||||
enum { Match = 0, NoMatch = 1, Error = 2 };
|
||||
|
||||
static void grep(FILE *, const char *, regex_t *);
|
||||
static void addpattern(const char *);
|
||||
static bool grep(FILE *, const char *);
|
||||
static void usage(void);
|
||||
|
||||
static bool eflag = false;
|
||||
static bool vflag = false;
|
||||
static bool many;
|
||||
static bool match = false;
|
||||
static char mode = 0;
|
||||
|
||||
static struct plist {
|
||||
char *pattern;
|
||||
regex_t preg;
|
||||
struct plist *next;
|
||||
} *phead;
|
||||
|
||||
int
|
||||
main(int argc, char *argv[])
|
||||
{
|
||||
bool match = false;
|
||||
struct plist *pnode, *tmp;
|
||||
int i, n, flags = REG_NOSUB;
|
||||
regex_t preg;
|
||||
FILE *fp;
|
||||
|
||||
ARGBEGIN {
|
||||
|
|
@ -30,6 +38,10 @@ main(int argc, char *argv[])
|
|||
flags |= REG_EXTENDED;
|
||||
break;
|
||||
case 'c':
|
||||
case 'e':
|
||||
addpattern(EARGF(usage()));
|
||||
eflag = true;
|
||||
break;
|
||||
case 'l':
|
||||
case 'n':
|
||||
case 'q':
|
||||
|
|
@ -45,57 +57,97 @@ main(int argc, char *argv[])
|
|||
usage();
|
||||
} ARGEND;
|
||||
|
||||
if(argc == 0)
|
||||
if(argc == 0 && !eflag)
|
||||
usage(); /* no pattern */
|
||||
|
||||
if((n = regcomp(&preg, argv[0], flags)) != 0) {
|
||||
char buf[BUFSIZ];
|
||||
/* If -e is not specified treat it as if it were */
|
||||
if(!eflag) {
|
||||
addpattern(argv[0]);
|
||||
argc--;
|
||||
argv++;
|
||||
}
|
||||
|
||||
regerror(n, &preg, buf, sizeof buf);
|
||||
enprintf(Error, "invalid pattern: %s\n", buf);
|
||||
/* Compile regex for all search patterns */
|
||||
for(pnode = phead; pnode; pnode = pnode->next) {
|
||||
if((n = regcomp(&pnode->preg, pnode->pattern, flags)) != 0) {
|
||||
char buf[BUFSIZ];
|
||||
|
||||
regerror(n, &pnode->preg, buf, sizeof buf);
|
||||
enprintf(Error, "invalid pattern: %s\n", buf);
|
||||
}
|
||||
}
|
||||
many = (argc > 1);
|
||||
if(argc == 1)
|
||||
grep(stdin, "<stdin>", &preg);
|
||||
else for(i = 1; i < argc; i++) {
|
||||
if(!(fp = fopen(argv[i], "r")))
|
||||
enprintf(Error, "fopen %s:", argv[i]);
|
||||
grep(fp, argv[i], &preg);
|
||||
fclose(fp);
|
||||
if(argc == 0) {
|
||||
match = grep(stdin, "<stdin>");
|
||||
} else {
|
||||
for(i = 0; i < argc; i++) {
|
||||
if(!(fp = fopen(argv[i], "r")))
|
||||
enprintf(Error, "fopen %s:", argv[i]);
|
||||
if(grep(fp, argv[i]))
|
||||
match = true;
|
||||
fclose(fp);
|
||||
}
|
||||
}
|
||||
pnode = phead;
|
||||
while(pnode) {
|
||||
tmp = pnode->next;
|
||||
regfree(&pnode->preg);
|
||||
free(pnode->pattern);
|
||||
free(pnode);
|
||||
pnode = tmp;
|
||||
}
|
||||
return match ? Match : NoMatch;
|
||||
}
|
||||
|
||||
void
|
||||
grep(FILE *fp, const char *str, regex_t *preg)
|
||||
addpattern(const char *pattern)
|
||||
{
|
||||
struct plist *pnode;
|
||||
|
||||
pnode = malloc(sizeof(*pnode));
|
||||
if(!pnode)
|
||||
eprintf("malloc:");
|
||||
pnode->pattern = strdup(pattern);
|
||||
if(!pnode->pattern)
|
||||
eprintf("strdup:");
|
||||
pnode->next = phead;
|
||||
phead = pnode;
|
||||
}
|
||||
|
||||
bool
|
||||
grep(FILE *fp, const char *str)
|
||||
{
|
||||
char *buf = NULL;
|
||||
long n, c = 0;
|
||||
size_t size = 0, len;
|
||||
struct plist *pnode;
|
||||
bool match = false;
|
||||
|
||||
for(n = 1; afgets(&buf, &size, fp); n++) {
|
||||
if(buf[(len = strlen(buf))-1] == '\n')
|
||||
buf[--len] = '\0';
|
||||
if(regexec(preg, buf, 0, NULL, 0) ^ vflag)
|
||||
continue;
|
||||
switch(mode) {
|
||||
case 'c':
|
||||
c++;
|
||||
break;
|
||||
case 'l':
|
||||
puts(str);
|
||||
goto end;
|
||||
case 'q':
|
||||
exit(Match);
|
||||
default:
|
||||
if(many)
|
||||
printf("%s:", str);
|
||||
if(mode == 'n')
|
||||
printf("%ld:", n);
|
||||
printf("%s\n", buf);
|
||||
break;
|
||||
for(pnode = phead; pnode; pnode = pnode->next) {
|
||||
if(buf[(len = strlen(buf))-1] == '\n')
|
||||
buf[--len] = '\0';
|
||||
if(regexec(&pnode->preg, buf, 0, NULL, 0) ^ vflag)
|
||||
continue;
|
||||
switch(mode) {
|
||||
case 'c':
|
||||
c++;
|
||||
break;
|
||||
case 'l':
|
||||
puts(str);
|
||||
goto end;
|
||||
case 'q':
|
||||
exit(Match);
|
||||
default:
|
||||
if(many)
|
||||
printf("%s:", str);
|
||||
if(mode == 'n')
|
||||
printf("%ld:", n);
|
||||
printf("%s\n", buf);
|
||||
break;
|
||||
}
|
||||
match = true;
|
||||
}
|
||||
match = true;
|
||||
}
|
||||
if(mode == 'c')
|
||||
printf("%ld\n", c);
|
||||
|
|
@ -103,10 +155,11 @@ end:
|
|||
if(ferror(fp))
|
||||
enprintf(Error, "%s: read error:", str);
|
||||
free(buf);
|
||||
return match;
|
||||
}
|
||||
|
||||
void
|
||||
usage(void)
|
||||
{
|
||||
enprintf(Error, "usage: %s [-Ecilnqv] pattern [files...]\n", argv0);
|
||||
enprintf(Error, "usage: %s [-Ecilnqv] [-e pattern] pattern [files...]\n", argv0);
|
||||
}
|
||||
|
|
|
|||
Loading…
Reference in New Issue