Why is more data printed than I expect?

Question

It's the next part of another problem I have just yesterday Awk doesn't match all match all my entries. I want to replace awk with perl and my first goal is to extract my declarations of functions in a .c and put it in a .h. So I came up with this :

cat dict3.c | perl -ne '/([a-z_*]+[[:space:]]+[a-z_*]+[[:space:]]*\(.*?\))/i; print $1 . ";\n"'

But the output is that :

    ;
;
;
;
;
;
;
;
dictent_t* dictentcreate(const char * key, const char * val);
dictent_t* dictentcreate(const char * key, const char * val);
dictent_t* dictentcreate(const char * key, const char * val);
dictent_t* dictentcreate(const char * key, const char * val);
dictent_t* dictentcreate(const char * key, const char * val);
dictent_t* dictentcreate(const char * key, const char * val);
dictent_t* dictentcreate(const char * key, const char * val);
dictent_t* dictentcreate(const char * key, const char * val);
dictent_t* dictentcreate(const char * key, const char * val);
dictent_t* dictentcreate(const char * key, const char * val);
dictent_t* dictentcreate(const char * key, const char * val);
dictent_t* dictentcreate(const char * key, const char * val);
dictent_t* dictentcreate(const char * key, const char * val);
dictent_t* dictentcreate(const char * key, const char * val);
dictent_t* dictentcreate(const char * key, const char * val);
dictent_t* dictentcreate(const char * key, const char * val);
dictent_t* dictentcreate(const char * key, const char * val);
dictent_t* dictentcreate(const char * key, const char * val);
dict_t* dictcreate();
dict_t* dictcreate();
dict_t* dictcreate();
dict_t* dictcreate();
dict_t* dictcreate();
dict_t* dictcreate();
dict_t* dictcreate();
dict_t* dictcreate();
dict_t* dictcreate();
dict_t* dictcreate();
dict_t* dictcreate();
dict_t* dictcreate();
dict_t* dictcreate();
dict_t* dictcreate();
dict_t* dictcreate();
dict_t* dictcreate();
void dictdestroy(*dict_t d);
void dictdestroy(*dict_t d);
void dictdestroy(*dict_t d);
void dictdestroy(*dict_t d);
void dictdestroy(*dict_t d);
void dictdestroy(*dict_t d);
void dictdestroy(*dict_t d);
void dictdestroy(*dict_t d);
void dictdestroy(*dict_t d);
void dictdestroy(*dict_t d);
void dictdestroy(*dict_t d);
void dictdestroy(*dict_t d);
void dictdestroy(*dict_t d);
void dictdestroy(*dict_t d);
void dictdestroy(*dict_t d);
void dictdestroy(*dict_t d);
void dictdump(dict_t *d);
void dictdump(dict_t *d);
void dictdump(dict_t *d);
void dictdump(dict_t *d);
void dictdump(dict_t *d);
void dictdump(dict_t *d);
void dictdump(dict_t *d);
void dictdump(dict_t *d);
void dictdump(dict_t *d);
void dictdump(dict_t *d);
void dictdump(dict_t *d);
void dictdump(dict_t *d);
int dictlook(dict_t *d, const char * key);
int dictlook(dict_t *d, const char * key);
int dictlook(dict_t *d, const char * key);
int dictlook(dict_t *d, const char * key);
int dictlook(dict_t *d, const char * key);
int dictlook(dict_t *d, const char * key);
int dictlook(dict_t *d, const char * key);
int dictlook(dict_t *d, const char * key);
int dictlook(dict_t *d, const char * key);
int dictlook(dict_t *d, const char * key);
int dictlook(dict_t *d, const char * key);
int dictlook(dict_t *d, const char * key);
int dictlook(dict_t *d, const char * key);
int dictlook(dict_t *d, const char * key);
int dictget(char* s, dict_t *d, const char *key);
int dictget(char* s, dict_t *d, const char *key);
int dictget(char* s, dict_t *d, const char *key);
int dictget(char* s, dict_t *d, const char *key);
int dictget(char* s, dict_t *d, const char *key);
int dictget(char* s, dict_t *d, const char *key);
int dictget(char* s, dict_t *d, const char *key);
int dictget(char* s, dict_t *d, const char *key);
int dictget(char* s, dict_t *d, const char *key);
int dictget(char* s, dict_t *d, const char *key);
int dictget(char* s, dict_t *d, const char *key);
int dictget(char* s, dict_t *d, const char *key);
int dictget(char* s, dict_t *d, const char *key);
int dictget(char* s, dict_t *d, const char *key);
int dictget(char* s, dict_t *d, const char *key);
dict_t* dictadd(dict_t* d, const char * key, const char * val);
dict_t* dictadd(dict_t* d, const char * key, const char * val);
dict_t* dictadd(dict_t* d, const char * key, const char * val);
dict_t* dictadd(dict_t* d, const char * key, const char * val);
dict_t* dictadd(dict_t* d, const char * key, const char * val);
dict_t* dictadd(dict_t* d, const char * key, const char * val);
dict_t* dictadd(dict_t* d, const char * key, const char * val);
dict_t* dictadd(dict_t* d, const char * key, const char * val);
dict_t* dictadd(dict_t* d, const char * key, const char * val);
dict_t* dictadd(dict_t* d, const char * key, const char * val);
dict_t* dictadd(dict_t* d, const char * key, const char * val);
dict_t* dictadd(dict_t* d, const char * key, const char * val);
dict_t* dictadd(dict_t* d, const char * key, const char * val);
dict_t* dictadd(dict_t* d, const char * key, const char * val);
dict_t* dictadd(dict_t* d, const char * key, const char * val);
dict_t* dictadd(dict_t* d, const char * key, const char * val);
dict_t* dictadd(dict_t* d, const char * key, const char * val);
dict_t* dictadd(dict_t* d, const char * key, const char * val);
dict_t* dictadd(dict_t* d, const char * key, const char * val);
dict_t* dictadd(dict_t* d, const char * key, const char * val);
dict_t* dictadd(dict_t* d, const char * key, const char * val);
dict_t* dictadd(dict_t* d, const char * key, const char * val);
dict_t* dictadd(dict_t* d, const char * key, const char * val);
dict_t* dictadd(dict_t* d, const char * key, const char * val);
dict_t* dictadd(dict_t* d, const char * key, const char * val);
dict_t* dictadd(dict_t* d, const char * key, const char * val);
dict_t* dictadd(dict_t* d, const char * key, const char * val);
dict_t* dictadd(dict_t* d, const char * key, const char * val);
dict_t* dictadd(dict_t* d, const char * key, const char * val);
dict_t* dictadd(dict_t* d, const char * key, const char * val);
dict_t* dictadd(dict_t* d, const char * key, const char * val);
dict_t* dictadd(dict_t* d, const char * key, const char * val);
dict_t dictup(dict_t d, const char * key, const char * newval);
dict_t dictup(dict_t d, const char * key, const char * newval);
dict_t dictup(dict_t d, const char * key, const char * newval);
dict_t dictup(dict_t d, const char * key, const char * newval);
dict_t dictup(dict_t d, const char * key, const char * newval);
dict_t dictup(dict_t d, const char * key, const char * newval);
dict_t dictup(dict_t d, const char * key, const char * newval);
dict_t dictup(dict_t d, const char * key, const char * newval);
dict_t dictup(dict_t d, const char * key, const char * newval);
dict_t dictup(dict_t d, const char * key, const char * newval);
dict_t dictup(dict_t d, const char * key, const char * newval);
dict_t dictup(dict_t d, const char * key, const char * newval);
dict_t dictup(dict_t d, const char * key, const char * newval);
dict_t dictup(dict_t d, const char * key, const char * newval);
dict_t dictup(dict_t d, const char * key, const char * newval);
dict_t dictup(dict_t d, const char * key, const char * newval);
dict_t dictup(dict_t d, const char * key, const char * newval);
dict_t dictup(dict_t d, const char * key, const char * newval);
dict_t dictup(dict_t d, const char * key, const char * newval);
dict_t dictup(dict_t d, const char * key, const char * newval);
dict_t dictup(dict_t d, const char * key, const char * newval);
dict_t dictup(dict_t d, const char * key, const char * newval);
dict_t dictup(dict_t d, const char * key, const char * newval);
dict_t* dictrm(dict_t* d, const char * key);
dict_t* dictrm(dict_t* d, const char * key);
dict_t* dictrm(dict_t* d, const char * key);
dict_t* dictrm(dict_t* d, const char * key);
dict_t* dictrm(dict_t* d, const char * key);
dict_t* dictrm(dict_t* d, const char * key);
dict_t* dictrm(dict_t* d, const char * key);
dict_t* dictrm(dict_t* d, const char * key);
dict_t* dictrm(dict_t* d, const char * key);
dict_t* dictrm(dict_t* d, const char * key);
dict_t* dictrm(dict_t* d, const char * key);
dict_t* dictrm(dict_t* d, const char * key);
dict_t* dictrm(dict_t* d, const char * key);
dict_t* dictrm(dict_t* d, const char * key);
dict_t* dictrm(dict_t* d, const char * key);
dict_t* dictrm(dict_t* d, const char * key);
dict_t* dictrm(dict_t* d, const char * key);
dict_t* dictrm(dict_t* d, const char * key);
dict_t* dictrm(dict_t* d, const char * key);
dict_t* dictrm(dict_t* d, const char * key);
dict_t* dictrm(dict_t* d, const char * key);
dict_t* dictrm(dict_t* d, const char * key);
dict_t* dictrm(dict_t* d, const char * key);
dict_t* dictrm(dict_t* d, const char * key);

Whereas there's just one declaration for each function in the file. I have no clue what it could be because the number of repetitions is not the same for each printed line so it can't be just one loop...

Is that the output or is that the input, or a combination of both ? — , Oct 15 '15 at 19:39

score 4 · Answer 1 · answered Oct 15 '15 at 19:22

4

Because you're not making the print command conditional upon matching the regex. Try this:

perl -ne '/([\w*]+\s+[\w*]+\s*\(.*?\))/i and print $1 . ";\n"' dict3.c
# .......................................^^^

For every line, you were printing the matched text from the last successful match.

answered Oct 15 '15 at 19:22

glenn jackman

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Ok, as I am new too perl I didn't know that syntax, but now I have the Llama with me ! Thank you – Nicolas Scotto Di Perto Oct 15 '15 at 20:04
@NicolasScottoDiPerto - You probably don't need to learn a lot for this. It's just a shorthand way of saying `if ( $_ =~ /.../ ) { print $1,"\n";}` – Oct 15 '15 at 20:42

Why is more data printed than I expect?

1 Answers1