cracraft@ccicpg.UUCP (Stuart Cracraft) (07/18/87)
Suppose you have a line from a file such as:
str1 str2 str3 str4 ... strN # strN+1 ... strN+I
^ ^ ^
| | |
Store in s1 | |
Store in s2 Store in s3
The above line consists of three fields:
1) str1
2) str2 ... strN (where N is up to 10)
3) strN+1 ... strN+I (where I is up to 10)
(strX represents an arbitrary-length string, up to 20 characters.)
You want to use scanf to parse this line, storing
each of the three fields in its own variable. The obvious
scanf("%s %[^#] %s",s1,s2,s3)
successfully parses s1 & s2, but doesn't correctly parse s3.
How do you use scanf to do it?
Stuartlopez@uiucdcsp.cs.uiuc.edu (07/19/87)
/*I only answer the easy ones*/
main()
{
char s1[100], s2[100], s3[100];
sscanf("one two three four # five six seven", "%s %[^#] \# %[^$]", s1, s2, s3);
printf("s1=%s, s2=%s, s3=%s\n", s1, s2, s3);
} /*main*/
This works on my compiler. I hope this is what you wanted.
FML
Somewhere out there.rlk@chinet.UUCP (Richard Klappal) (07/19/87)
In article <1220@ccicpg.UUCP> cracraft@ccicpg.UUCP (Stuart Cracraft) writes: >Suppose you have a line from a file such as: > >str1 str2 str3 str4 ... strN # strN+1 ... strN+I > ^ ^ ^ > | | | > Store in s1 | | > Store in s2 Store in s3 > ..... >each of the three fields in its own variable. The obvious > scanf("%s %[^#] %s",s1,s2,s3) >successfully parses s1 & s2, but doesn't correctly parse s3. >How do you use scanf to do it? > Stuart Since the number of strings following the '#' may be variable, I would use strtok (see strings(3)), if you have it. { if not, look thru the net.sources, or mod.sources, archives for Henry Spencer's strings package. } ... fgets(stream, MAXLINE, buffer); strcpy(s1,strtok(buffer," ")); strcpy(s2,strtok(NULL,"#")); strcpy(s3,strtok(NULL,"\n")); I have not included any error checking in this example, but you should do so since strtok() returns NULL when no token remains. -- --- UUCP: ..!ihnp4!chinet!uklpl!rlk || MCIMail: rklappal || Compuserve: 74106,1021 ..!ihnp4!ihu1h!rlk ---
dcm@sfsup.UUCP (David C. Miller, consultant) (07/22/87)
In article <1220@ccicpg.UUCP> cracraft@ccicpg.UUCP (Stuart Cracraft) writes: >Suppose you have a line from a file such as: > >str1 str2 str3 str4 ... strN # strN+1 ... strN+I > ^ ^ ^ > | | | > Store in s1 | | > Store in s2 Store in s3 > >The above line consists of three fields: > 1) str1 > 2) str2 ... strN (where N is up to 10) > 3) strN+1 ... strN+I (where I is up to 10) >(strX represents an arbitrary-length string, up to 20 characters.) > >You want to use scanf to parse this line, storing >each of the three fields in its own variable. The obvious > > scanf("%s %[^#] %s",s1,s2,s3) > >successfully parses s1 & s2, but doesn't correctly parse s3. > >How do you use scanf to do it? > > Stuart There are two problems with the format you used. 1. There is no provision for disposing of the '#'. 2. Field 3 is specified as ONE space separated field. Correction follows: scanf("%s %[^#]# %[^\n]\n", s1, s2, s3); ^ ^ ^ | | +---- Clean up newline | +-------- Field 3 is everything up to newline +------------- Clean up # The newline may be replaced with any other character you may use to designate end-of-line. Hope this helps. Dave David C. Miller, consultant Comm Addresses: Paperware: AT&T Information Systems,190 River Road,Summit,NJ 07901 Liveware: (201) 522-6107 Software: {allegra,burl,cbosgd,clyde,ihnp4,ulysses}!sfsup!dcm
cracraft@ccicpg.UUCP (Stuart Cracraft) (07/24/87)
There were a number of replies to this quiz question. Only one person answered the question correctly. First, let me restate the quiz question: >Suppose you have an input line of the form: > >str1 str2 str3 str4 ... strN # strN+1 ... strN+I > ^ ^ ^ > | | | > Store in s1 | | > Store in s2 Store in s3 > >The above line consists of three fields: > 1) str1 > 2) str2 ... strN (where N is up to 10) > 3) strN+1 ... strN+I (where I is up to 10) >(strX represents an arbitrary-length string, up to 20 characters.) >How do you parse this line using scanf? Many people correctly answered for the first argument. It is simply %s in the scanf scan string. Some people, though fewer, correctly answered for the second argument. It is simply [^#] in the scan string. This takes advantage of the scanf ^ 'complement' operator to create a 'breakset'. When it came to the third argument however, just about everyone missed, except for our winner. Our winner correctly pointed out that a non-assignment argument must also be supplied, and he correctly deduced the breakset for the final argument as well. Here is the correct answer: scanf("%s %[^#] %*c %[^\n]",s1,s2,s3); Congratulations to our winner, Leonard Binns! Stuart P.S. Other answers may exist. The quiz manufacturer disclaims any responsibility for additional solutions.