K&R2 section 1.5.1 - "getchar" problem

[arnuld]

i have slightly modified the programme from section 1.5.1 which takes
the input frm keyboard and then prints that to the terminal. it just
does not run and i am unable to understand the error message.

may you tell me what is wrong and how to make that right ?

------------------------------ INPUT ---------------------
#include <stdio.h>

int main() {
int c;

while((c = getchar()) != EOF)
{
printf("your input: ");
putchar(c);
printf("\n");
}

return 0;
}

--------------------- OUTPUT -----------------------------
[arch@voodo kr2]$ gcc -ansi -pedantic -Wall -Wextra 151.c
151.c:1: error: expected identifier or '(' before '/' token
151.c:2:12: error: too many decimal points in number
In file included from /usr/include/_G_config.h:44,
from /usr/include/libio.h:32,
from /usr/include/stdio.h:72,
from 151.c:4:
/usr/include/gconv.h:72: error: expected declaration specifiers or
'...' before 'size_t'
/usr/include/gconv.h:88: error: expected declaration specifiers or
'...' before 'size_t'
/usr/include/gconv.h:97: error: expected declaration specifiers or
'...' before 'size_t'
/usr/include/gconv.h:174: error: expected specifier-qualifier-list
before 'size_t'
In file included from /usr/include/stdio.h:72,
from 151.c:4:
/usr/include/libio.h:328: error: expected specifier-qualifier-list
before 'size_t'
/usr/include/libio.h:360: error: expected declaration specifiers or
'...' before 'size_t'
/usr/include/libio.h:369: error: expected declaration specifiers or
'...' before 'size_t'
/usr/include/libio.h:485: error: expected '=', ',', ';', 'asm' or
'__attribute__' before '_IO_sgetn'
In file included from 151.c:4:
/usr/include/stdio.h:306: error: expected declaration specifiers or
'...' before 'size_t'
/usr/include/stdio.h:608: error: expected '=', ',', ';', 'asm' or
'__attribute__' before 'fread'
/usr/include/stdio.h:614: error: expected '=', ',', ';', 'asm' or
'__attribute__' before 'fwrite'
[arch@voodo kr2]$

[Sheth Raxit]

On Mar 8, 11:07 am, "arnuld" <geek.arn...@gm ail.comwrote:

i have slightly modified the programme from section 1.5.1 which takes
the input frm keyboard and then prints that to the terminal. it just
does not run and i am unable to understand the error message.

may you tell me what is wrong and how to make that right ?

refer this link,
http://gcc.gnu.org/ml/gcc/2005-03/msg00865.html

if its match with your configuration (OS+compiler+li bs+headers) apply
latest patch or do needful.

>
------------------------------ INPUT ---------------------
#include <stdio.h>

int main() {
int c;

while((c = getchar()) != EOF)
{
printf("your input: ");
putchar(c);
printf("\n");
}

return 0;

}

--------------------- OUTPUT -----------------------------
[arch@voodo kr2]$ gcc -ansi -pedantic -Wall -Wextra 151.c

I dont think -Wextra needed (or it is there) after -Wall

151.c:1: error: expected identifier or '(' before '/' token
151.c:2:12: error: too many decimal points in number
In file included from /usr/include/_G_config.h:44,
from /usr/include/libio.h:32,
from /usr/include/stdio.h:72,
from 151.c:4:
/usr/include/gconv.h:72: error: expected declaration specifiers or
'...' before 'size_t'
/usr/include/gconv.h:88: error: expected declaration specifiers or
'...' before 'size_t'
/usr/include/gconv.h:97: error: expected declaration specifiers or
'...' before 'size_t'
/usr/include/gconv.h:174: error: expected specifier-qualifier-list
before 'size_t'
In file included from /usr/include/stdio.h:72,
from 151.c:4:
/usr/include/libio.h:328: error: expected specifier-qualifier-list
before 'size_t'
/usr/include/libio.h:360: error: expected declaration specifiers or
'...' before 'size_t'
/usr/include/libio.h:369: error: expected declaration specifiers or
'...' before 'size_t'
/usr/include/libio.h:485: error: expected '=', ',', ';', 'asm' or
'__attribute__' before '_IO_sgetn'
In file included from 151.c:4:
/usr/include/stdio.h:306: error: expected declaration specifiers or
'...' before 'size_t'
/usr/include/stdio.h:608: error: expected '=', ',', ';', 'asm' or
'__attribute__' before 'fread'
/usr/include/stdio.h:614: error: expected '=', ',', ';', 'asm' or
'__attribute__' before 'fwrite'
[arch@voodo kr2]$

posted to gcc.gnu.help so u may got more help from other people.

Its failed telling
"Google Groups does not currently support posting to the following
usenet groups: "gcc.gnu.he lp" " but you may try there.


--Raxit Sheth

[Zhou Yan]

"arnuld" <ge*********@gm ail.comwrites:

i have slightly modified the programme from section 1.5.1 which takes
the input frm keyboard and then prints that to the terminal. it just
does not run and i am unable to understand the error message.

may you tell me what is wrong and how to make that right ?

------------------------------ INPUT ---------------------
#include <stdio.h>

int main() {
int c;

while((c = getchar()) != EOF)
{
printf("your input: ");
putchar(c);
printf("\n");
}

return 0;
}

--------------------- OUTPUT -----------------------------
[arch@voodo kr2]$ gcc -ansi -pedantic -Wall -Wextra 151.c
151.c:1: error: expected identifier or '(' before '/' token
151.c:2:12: error: too many decimal points in number
In file included from /usr/include/_G_config.h:44,
from /usr/include/libio.h:32,
from /usr/include/stdio.h:72,
from 151.c:4:
/usr/include/gconv.h:72: error: expected declaration specifiers or
'...' before 'size_t'
/usr/include/gconv.h:88: error: expected declaration specifiers or
'...' before 'size_t'
/usr/include/gconv.h:97: error: expected declaration specifiers or
'...' before 'size_t'
/usr/include/gconv.h:174: error: expected specifier-qualifier-list
before 'size_t'
In file included from /usr/include/stdio.h:72,
from 151.c:4:
/usr/include/libio.h:328: error: expected specifier-qualifier-list
before 'size_t'
/usr/include/libio.h:360: error: expected declaration specifiers or
'...' before 'size_t'
/usr/include/libio.h:369: error: expected declaration specifiers or
'...' before 'size_t'
/usr/include/libio.h:485: error: expected '=', ',', ';', 'asm' or
'__attribute__' before '_IO_sgetn'
In file included from 151.c:4:
/usr/include/stdio.h:306: error: expected declaration specifiers or
'...' before 'size_t'
/usr/include/stdio.h:608: error: expected '=', ',', ';', 'asm' or
'__attribute__' before 'fread'
/usr/include/stdio.h:614: error: expected '=', ',', ';', 'asm' or
'__attribute__' before 'fwrite'
[arch@voodo kr2]$

I just tried your program, no problem...are you sure you are post
exactly what you input?

[Keith Thompson]

"arnuld" <ge*********@gm ail.comwrites:

i have slightly modified the programme from section 1.5.1 which takes
the input frm keyboard and then prints that to the terminal. it just
does not run and i am unable to understand the error message.

may you tell me what is wrong and how to make that right ?

------------------------------ INPUT ---------------------
#include <stdio.h>

int main() {
int c;

while((c = getchar()) != EOF)
{
printf("your input: ");
putchar(c);
printf("\n");
}

return 0;
}

--------------------- OUTPUT -----------------------------
[arch@voodo kr2]$ gcc -ansi -pedantic -Wall -Wextra 151.c
151.c:1: error: expected identifier or '(' before '/' token
151.c:2:12: error: too many decimal points in number

[more error messages snipped]

When I compile your program with the same options, it compiles without
errors or warnings and works properly. Probably your <stdio.hheade r
is messed up and/or your compiler is misconfigured.

I'm assuming the code you posted is exactly what you compiled
(copy-and-pasted, not re-typed).

Try compiling a C source file consisting only of a single line:

#include <stdio.h>

You'll probably see the same problem.

If I'm right, this is a question for gnu.gcc.help. Be sure to tell
them the details of your system (what operating system, what version
of gcc, and how gcc was installed); such details are usually off-topic
here, but often vital in tracking down a compiler-specific problem.

--
Keith Thompson (The_Other_Keit h) ks***@mib.org <http://www.ghoti.net/~kst>
San Diego Supercomputer Center <* <http://users.sdsc.edu/~kst>
"We must do something. This is something. Therefore, we must do this."
-- Antony Jay and Jonathan Lynn, "Yes Minister"

[arnuld]

On Mar 8, 11:34 am, Keith Thompson <[e-mail] ote:

When I compile your program with the same options, it compiles without
errors or warnings and works properly. Probably your <stdio.hheade r
is messed up and/or your compiler is misconfigured.

I'm assuming the code you posted is exactly what you compiled
(copy-and-pasted, not re-typed).

YES, i did copy-paste.

Try compiling a C source file consisting only of a single line:

#include <stdio.h>
You'll probably see the same problem.

no trouble with that.

If I'm right, this is a question for gnu.gcc.help. Be sure to tell
them the details of your system (what operating system, what version
of gcc, and how gcc was installed); such details are usually off-topic
here, but often vital in tracking down a compiler-specific problem.

i do not know BUT this time, i *copied* the programme from my *post*
here to *emacs* and it worked, i do not how. this is th output:
[arch@voodo kr2]$ ./a.out
a
your input: a
your input:

b
your input: b
your input:

[arch@voodo kr2]$

why i am getting "your input" 2 times, instead of one ?

--
Keith Thompson (The_Other_Keit h) [e-mail] <http://www.ghoti.net/~kst>
San Diego Supercomputer Center <* <http://users.sdsc.edu/~kst>
"We must do something. This is something. Therefore, we must do this."
-- Antony Jay and Jonathan Lynn, "Yes Minister"

[Keith Thompson]

"Sheth Raxit" <ra************ @yahoo.co.inwri tes:
[...]

posted to gcc.gnu.help so u may got more help from other people.

Its failed telling
"Google Groups does not currently support posting to the following
usenet groups: "gcc.gnu.he lp" " but you may try there.

It's gnu.gcc.help, not gcc.gnu.help.

Please don't use silly abbreviations like "u". This isn't a chat
room.

--
Keith Thompson (The_Other_Keit h) ks***@mib.org <http://www.ghoti.net/~kst>
San Diego Supercomputer Center <* <http://users.sdsc.edu/~kst>
"We must do something. This is something. Therefore, we must do this."
-- Antony Jay and Jonathan Lynn, "Yes Minister"

[Keith Thompson]

"arnuld" <ge*********@gm ail.comwrites:

>On Mar 8, 11:34 am, Keith Thompson <[e-mail] ote:
When I compile your program with the same options, it compiles without
errors or warnings and works properly. Probably your <stdio.hheade r
is messed up and/or your compiler is misconfigured.

I'm assuming the code you posted is exactly what you compiled
(copy-and-pasted, not re-typed).

YES, i did copy-paste.

>Try compiling a C source file consisting only of a single line:

#include <stdio.h>
You'll probably see the same problem.

no trouble with that.

>If I'm right, this is a question for gnu.gcc.help. Be sure to tell
them the details of your system (what operating system, what version
of gcc, and how gcc was installed); such details are usually off-topic
here, but often vital in tracking down a compiler-specific problem.

i do not know BUT this time, i *copied* the programme from my *post*
here to *emacs* and it worked, i do not how. this is th output:

The only thing I can think of is that your source file originally
contained some funny characters. If you still have the original file,
try "cat -A" or "cat -v" to display any control characters.

[arch@voodo kr2]$ ./a.out
a
your input: a
your input:

b
your input: b
your input:

[arch@voodo kr2]$

why i am getting "your input" 2 times, instead of one ?

Let me guess. You typed a letter 'a', then hit the return key.
That's two characters.

>--
Keith Thompson (The_Other_Keit h) [e-mail] <http://www.ghoti.net/~kst>
San Diego Supercomputer Center <* <http://users.sdsc.edu/~kst>
"We must do something. This is something. Therefore, we must do this."
-- Antony Jay and Jonathan Lynn, "Yes Minister"

Don't quote signatures unless you're commenting on them. (You've been
posting here long enough to know that.)

--
Keith Thompson (The_Other_Keit h) ks***@mib.org <http://www.ghoti.net/~kst>
San Diego Supercomputer Center <* <http://users.sdsc.edu/~kst>
"We must do something. This is something. Therefore, we must do this."
-- Antony Jay and Jonathan Lynn, "Yes Minister"

[arnuld]

On Mar 8, 12:17 pm, Keith Thompson <[e-mail] ote:

The only thing I can think of is that your source file originally
contained some funny characters.

yes, it did contain some *funny* characters. actually they were at the
beginning of programme. they look like:

// K&R2 section 1.5.1
//

i was writing C++ in C

now i see compiler *did* mention that:

151.c:1: error: expected identifier or '(' before '/' token

[arch@voodo kr2]$ ./a.out
a
your input: a
your input:

b
your input: b
your input:

[arch@voodo kr2]$

why i am getting "your input" 2 times, instead of one ?

Let me guess. You typed a letter 'a', then hit the return key.
That's two characters.

NO, i am not talking about characters. i am talking about "words":
your input

after getchar(), there must be one sentence:

"your input: a"
but i get 2 sentences. 2nd one is:

"your input: "
why so ? (when i have used it once only in programme)

Don't quote signatures unless you're commenting on them. (You've been
posting here long enough to know that.)

sorry.

BTW, that was an accident, happened because i was careless.

[Keith Thompson]

"arnuld" <ge*********@gm ail.comwrites:

>On Mar 8, 12:17 pm, Keith Thompson <[e-mail] ote:

>The only thing I can think of is that your source file originally
contained some funny characters.

yes, it did contain some *funny* characters. actually they were at the
beginning of programme. they look like:

// K&R2 section 1.5.1
//

i was writing C++ in C

"//" comments are also allowed in C99, and gcc accepts them as an
extension in certain modes. With the options you used, it doesn't
recognize them.

The lesson: copy-and-paste the entire source file. If you fed it to
the compiler, we need to see it.

[...]

[arch@voodo kr2]$ ./a.out
a
your input: a
your input:

b
your input: b
your input:

[arch@voodo kr2]$

why i am getting "your input" 2 times, instead of one ?

>Let me guess. You typed a letter 'a', then hit the return key.
That's two characters.

NO, i am not talking about characters. i am talking about "words":
your input

after getchar(), there must be one sentence:

"your input: a"
but i get 2 sentences. 2nd one is:

"your input: "
why so ? (when i have used it once only in programme)

[...]

Here's your program (with the invalid comments deleted):

#include <stdio.h>

int main() {
int c;

while((c = getchar()) != EOF)
{
printf("your input: ");
putchar(c);
printf("\n");
}

return 0;
}

You call getchar() in a loop. The loop, which includes printing the
message "your input: ", will be executed once for each input
character. You typed a total of 4 characters: 'a', newline, 'b',
newline. The "putchar(c) " statement printed the value of each one;
when it prints a newline, it produces a blank line in your output.

I advised you in another thread to read section 12 of the comp.lang.c
FAQ. Please do so before posting more questions.

--
Keith Thompson (The_Other_Keit h) ks***@mib.org <http://www.ghoti.net/~kst>
San Diego Supercomputer Center <* <http://users.sdsc.edu/~kst>
"We must do something. This is something. Therefore, we must do this."
-- Antony Jay and Jonathan Lynn, "Yes Minister"

[Nick Keighley]

arnuld wrote:

On Mar 8, 12:17 pm, Keith Thompson <[e-mail] ote:

It would help if you left in more context (eg. the program...)

The only thing I can think of is that your source file originally
contained some funny characters.

yes, it did contain some *funny* characters. actually they were at the
beginning of programme. they look like:

// K&R2 section 1.5.1
//

so you *didn't* post your exact code.

i was writing C++ in C

bad idea with a C compiler

now i see compiler *did* mention that:

151.c:1: error: expected identifier or '(' before '/' token

compilers do their best to tell you what the problem is

[arch@voodo kr2]$ ./a.out
a
your input: a
your input:

b
your input: b
your input:

[arch@voodo kr2]$

why i am getting "your input" 2 times, instead of one ?

Let me guess. You typed a letter 'a', then hit the return key.
That's two characters.

NO, i am not talking about characters.

well you should be. Your code was similar to this

while ((c = getchar()) != EOF)
printf ("your input %c\n", c);

so it keeps printing the line "your input..." until it gets an EOF.
You typed two characters ('a' and '\n') that weren't EOF, hence
two lines of output. (ok, technically, EOF isn't a character...)

i am talking about "words":
your input

after getchar(), there must be one sentence:

"your input: a"

but i get 2 sentences. 2nd one is:

"your input: "

why so ? (when i have used it once only in programme)

Don't quote signatures unless you're commenting on them. (You've been
posting here long enough to know that.)

sorry.

BTW, that was an accident, happened because i was careless.

--
Nick Keighley