How to grep only if pattern1 and pattern2 matches in consecutive lines - grep

Question

I have a file like below:
city-italy
good food
bad climate
-
city-india
bad food
normal climate
-
city-brussel
normal dressing
stylish cookings
good food
-
Question - I want to grep city and food, for which "food" is "bad".
For example -
for the above question, i need a grep command to get a answer like below
city-india
bad food
Please help me like, how i will get pattern 1 and pattern 2 grepped only if both succeeds parallely.
i mean both pattern should match and it should grep in the following line.

Answer 1

You can do it with pipes - grep -A1 city <filename> | grep -B1 "bad food" or cat filename | grep -A1 city | grep -B1 "bad food" (or any other stream source for the pipe)

Answer 2

If the city name is guaranteed to come before the food quality (any other info in between is allowed):
sed -n -e '/^city/h' -e '/bad food/{x;G;p}' input
Which keeps the name of each city in the hold buffer and prints the last city name when matches bad food.

Answer 3

I know this is an old question, but here's a "robust" alternative (cuz I'm into that):
grep -x -e'city-.*' -e'good food' -e'bad food' -e'-' | tr \\n \| | sed -e's/|-|/\n/g' | grep -xe'[^|]\+|[^|]\+' | grep -e'|bad food$' | tr \| \\n
Explanation
grep -x -e'city-.*' -e'good food' -e'bad food' -e'-': only keep the lines that contain a "city line", a "food line" (either good or bad), or a "separator line" (the food line expression could be better, I know), the -x argument to grep will make it return a line only if the whole line matches the given expression (incidentally, this first stage makes the whole pipe not choke on differently-sized "registers"),
tr \\n \|: turn newlines into pipes (you can use any character that does not appear in the original file, pipe works, so does a colon, you get the idea),
sed -e's/|-|/\n/g': replace the |-| string by a newline (this are the places we know a "register" ends, since we only kept the datums we're interested in and the separators, we know that now we have each of our "registers" in a single line, with their fields separated by pipes),
grep -xe'[^|]\+|[^|]\+': only keep lines containing exactly two fields (ie. the city and food fields),
grep -e'|bad food$': keep only lines ending in |bad food,
tr \| \\n: turn pipes back into newlines (nb. this is just here so that the output conforms to the question's specification, it's not really needed, nor preferred in my opinion).
Partial outputs
After grep -x -e'city-.*' -e'good food' -e'bad food' -e'-':
city-italy
good food
-
city-india
bad food
-
city-brussel
good food
-
After tr \\n \|:
city-italy|good food|-|city-india|bad food|-|city-brussel|good food|-|
After sed -e's/|-|/\n/g':
city-italy|good food
city-india|bad food
city-brussel|good food
After grep -xe'[^|]\+|[^|]\+': idem, since we don't have a "city line" without a "food line" in the example given, nor a register containing two "city lines" and a "food line", nor a register containing a "city line" and two "food lines", nor... you get the picture,
After grep -e'|bad food$':
city-india|bad food
After tr \| \\n:
city-india
bad food
Why is this more "robust"?
The input file basically consists of different "registers", each containing a variable number of "fields", but instead of having them in an "horizontal" format, we find them in a "vertical" one, ie. one field per line with a lone - separating whole registers.
The pipe above supports any amount of fields in each register, it only assumes that:
Registers are separated by a lone -,
The "city fields" are all of the form city-*,
The "food fields" are either good food or bad food,
If at all existent, "city" fields appear before "food" fields.
(this last one I find particularly hard to relax, at least in a "normal"-ish pipe like the one given).
I does not assume that:
Each register has a "city" and a "food" field,
Each register has only "city" and "food" fields.
Disclaimer
I'm not claiming this is in any way better than any of the other answers, it's just that I can't do sed or awk to save my own life, and often find pipes like this are helpful in understanding how the file gets filtered and transformed.
All in all, it's just a matter of taste.

Answer 4

If the order is ensured, you can use directly the command grep with OR:
grep -e "city" -e "food" FILE_INPUT
Then hopefully the city will follow by its food feature at following.
The result looks like:
city-italy
good food
city-india
bad food
city-brussel
good food
You can change your pattern to get a more filtered result.

Answer 5

To get city with bad food using gnu awk (due to RS)
awk '/bad food/ {print RS $1}' RS="city" file
city-india

Answer 6

another awk line:
kent$ awk 'BEGIN{FS=OFS="\n";RS="-"FS}/bad food/{print $1,$2}' file
city-india
bad food