How do I split a string on a delimiter in Bash

Question

I have this string stored in a variable   IN  bla some com john home com    Now I would like to split the strings by   delimiter so that I have   ADDR1  bla some com  ADDR2  john home com    I don t necessarily need the ADDR1 and ADDR2 variables  If they are elements of an array that s even better     After suggestions from the answers below  I ended up with the following which is what I was after      usr bin env bash  IN  bla some com john home com   mails   echo  IN   tr       n    for addr in  mails do     echo   gt    addr   done   Output    gt   bla some com   gt   john home com    There was a solution involving setting Internal field separator  IFS  to    I am not sure what happened with that answer  how do you reset IFS back to default   RE  IFS solution  I tried this and it works  I keep the old IFS and then restore it   IN  bla some com john home com   OIFS  IFS IFS     mails2  IN for x in  mails2 do     echo   gt    x   done  IFS  OIFS   BTW  when I tried   mails2   IN    I only got the first string when printing it in loop  without brackets around  IN it works

User · Answer

IN  bla some com john home com Charlie Brown  lt cbrown acme com       amp           are no problem simple is beautiful  -   set -f oldifs   IFS  IFS      arrayIN   IN  IFS   oldifs  for i in    arrayIN       do echo   i  done set  f   Output   bla some com john home com Charlie Brown  lt cbrown acme com       amp           are no problem simple is beautiful  -    Explanation  Simple assignment using parenthesis    converts semicolon separated list into an array provided you have correct IFS while doing that  Standard FOR loop handles individual items in that array as usual  Notice that the list given for IN variable must be  hard  quoted  that is  with single ticks    IFS must be saved and restored since Bash does not treat an assignment the same way as a command  An alternate workaround is to wrap the assignment inside a function and call that function with a modified IFS  In that case separate saving restoring of IFS is not needed  Thanks for  Bize  for pointing that out

User · Answer

The following Bash zsh function splits its first argument on the delimiter given by the second argument   split         local string   1      local delimiter   2      if   -n   string     then         local part         while read -d   delimiter  part  do             echo  part         done  lt  lt  lt    string          echo  part     fi     For instance  the command    split  a b c        yields  a b c   This output may  for instance  be piped to other commands  Example     split  a b c        cat -n 1   a 2   b 3   c   Compared to the other solutions given  this one has the following advantages    IFS is not overriden  Due to dynamic scoping of even local variables  overriding IFS over a loop causes the new value to leak into function calls performed from within the loop  Arrays are not used  Reading a string into an array using read requires the flag -a in Bash and -A in zsh    If desired  the function may be put into a script as follows      usr bin env bash  split                  split

User · Answer

Okay guys   Here s my answer   DELIMITER VAL      read -d    F ABOUT DISTRO R  lt  lt  EOF  DISTRIB ID Ubuntu DISTRIB RELEASE 14 04 DISTRIB CODENAME trusty DISTRIB DESCRIPTION  Ubuntu 14 04 4 LTS  NAME  Ubuntu  VERSION  14 04 4 LTS  Trusty Tahr  ID ubuntu ID LIKE debian PRETTY NAME  Ubuntu 14 04 4 LTS  VERSION ID  14 04  HOME URL  http   www ubuntu com   SUPPORT URL  http   help ubuntu com   BUG REPORT URL  http   bugs launchpad net ubuntu   EOF  SPLIT NOW   awk -F DELIMITER VAL   for i 1 i lt  NF i    printf   s n    i     lt  lt  lt    F ABOUT DISTRO R    while read -r line  do    SPLIT     line   done  lt  lt  lt    SPLIT NOW  for i in    SPLIT       do     echo   i  done   Why this approach is  the best  for me   Because of two reasons    You do not need to escape the delimiter  You will not have problem with blank spaces  The value will be properly separated in the array       s

User · Answer

In Android shell  most of the proposed methods just do not work     IFS     read -ra ADDR  lt  lt  lt   PATH                                system bin sh  can t create temporary file  sqlite stmt journals mksh EbNoR10629  No such file or directory   What does work is     for i in   PATH        do echo  i  done  sbin  vendor bin  system sbin  system bin  system xbin   where    means global replacement

User · Answer

Apart from the fantastic answers that were already provided  if it is just a matter of printing out the data you may consider using awk   awk -F      for  i 1 i lt  NF i    printf   gt    s  n    i     lt  lt  lt    IN    This sets the field separator to    so that it can loop through the fields with a for loop and print accordingly   Test    IN  bla some com john home com    awk -F      for  i 1 i lt  NF i    printf   gt    s  n    i     lt  lt  lt    IN   gt   bla some com   gt   john home com    With another input     awk -F      for  i 1 i lt  NF i    printf   gt    s  n    i     lt  lt  lt   a b c   d e  f   gt   a   gt   b   gt   c   d   gt   e    gt   f

User · Answer

you can apply awk to many situations  echo  bla some com john home com  awk -F      printf   s n s n    1   2     also you can use this  echo  bla some com john home com  awk -F      print  1  2   OFS   n

User · Answer

How about this approach   IN  bla some com john home com   set --   IN   IFS      declare -a Array       echo    Array       echo    Array 0     echo    Array 1       Source

User · Answer

Yet another late answer    If you are java minded  here is the bashj  https   sourceforge net projects bashj   solution      usr bin bashj    java  private static String   cuts  private static int cnt 0  public static void split String words String regexp   cuts words split regexp    public static String next    return cnt lt cuts length   cuts cnt       null        bash  IN  bla some com john home com     j split  IN           java method call  while true do     NAME j next         java method call     if    NAME    null     then echo  NAME   else exit   fi done

User · Answer

I think AWK is the best and efficient command to resolve your problem  AWK is included by default in almost every Linux distribution   echo  bla some com john home com    awk -F      print  1  2     will give  bla some com john home com   Of course your can store each email address by redefining the awk print field

User · Answer

This is the simplest way to do it   spo  one two three  OIFS  IFS IFS     spo array   spo  IFS  OIFS echo   spo array

User · Answer

This also works   IN  bla some com john home com  echo ADD1  echo  IN   cut -d    -f 1  echo ADD2  echo  IN   cut -d    -f 2    Be careful  this solution is not always correct  In case you pass  bla some com  only  it will assign it to both ADD1 and ADD2

User · Answer

You can set the internal field separator  IFS  variable  and then let it parse into an array  When this happens in a command  then the assignment to IFS only takes place to that single command s environment  to read    It then parses the input according to the IFS variable value into an array  which we can then iterate over   IFS     read -ra ADDR  lt  lt  lt    IN  for i in    ADDR       do       process   i  done   It will parse one line of items separated by    pushing it into an array  Stuff for processing whole of  IN  each time one line of input separated by      while IFS     read -ra ADDR  do       for i in    ADDR       do             process   i        done  done  lt  lt  lt    IN

User · Answer

Compatible answer There are a lot of different ways to do this in bash  However  it s important to first note that bash has many special features  so-called bashisms  that won t work in any other shell  In particular  arrays  associative arrays  and pattern substitution  which are used in the solutions in this post as well as others in the thread  are bashisms and may not work under other shells that many people use  For instance  on my Debian GNU Linux  there is a standard shell called dash  I know many people who like to use another shell called ksh  and there is also a special tool called busybox with his own shell interpreter  ash   Requested string The string to be split in the above question is  IN  quot bla some com john home com quot   I will use a modified version of this string to ensure that my solution is robust to strings containing whitespace  which could break other solutions  IN  quot bla some com john home com Full Name  lt fulnam other org gt  quot   Split string based on delimiter in bash  version  gt  4 2  In pure bash  we can create an array with elements split by a temporary value for IFS  the input field separator   The IFS  among other things  tells bash which character s  it should treat as a delimiter between elements when defining an array  IN  quot bla some com john home com Full Name  lt fulnam other org gt  quot     save original IFS value so we can restore it later oIFS  quot  IFS quot  IFS  quot   quot  declare -a fields   IN  IFS  quot  oIFS quot  unset oIFS  In newer versions of bash  prefixing a command with an IFS definition changes the IFS for that command only and resets it to the previous value immediately afterwards  This means we can do the above in just one line  IFS    read -a fields  lt  lt  lt  quot  IN quot    after this command  the IFS resets back to its previous value  here  the default   set   grep  IFS    IFS     t n   We can see that the string IN has been stored into an array named fields  split on the semicolons  set   grep  fields      IN    fields   0   quot bla some com quot   1   quot john home com quot   2   quot Full Name  lt fulnam other org gt  quot     IN  bla some com john home com Full Name  lt fulnam other org gt     We can also display the contents of these variables using declare -p   declare -p IN fields   declare -- IN  quot bla some com john home com Full Name  lt fulnam other org gt  quot    declare -a fields   0   quot bla some com quot   1   quot john home com quot   2   quot Full Name  lt fulnam other org gt  quot    Note that read is the quickest way to do the split because there are no forks or external resources called  Once the array is defined  you can use a simple loop to process each field  or  rather  each element in the array you ve now defined       quot   fields     quot   expands to return every element of  fields  array as a separate argument for x in  quot   fields     quot   do     echo  quot  gt    x  quot      done    gt   bla some com     gt   john home com     gt   Full Name  lt fulnam other org gt    Or you could drop each field from the array after processing using a shifting approach  which I like  while    quot  fields quot     do     echo  quot  gt    fields  quot        slice the array      fields   quot   fields    1  quot       done    gt   bla some com     gt   john home com     gt   Full Name  lt fulnam other org gt    And if you just want a simple printout of the array  you don t even need to loop over it  printf  quot  gt    s  n quot   quot   fields     quot     gt   bla some com     gt   john home com     gt   Full Name  lt fulnam other org gt    Update  recent bash  gt   4 4 In newer versions of bash  you can also play with the command mapfile  mapfile -td    fields  lt   lt  printf  quot  s 0 quot   quot  IN quot    This syntax preserve special chars  newlines and empty fields  If you don t want to include empty fields  you could do the following  mapfile -td    fields  lt  lt  lt  quot  IN quot  fields   quot   fields       n   quot       drop   n  added by   lt  lt  lt    With mapfile  you can also skip declaring an array and implicitly  quot loop quot  over the delimited elements  calling a function on each  myPubliMail         printf  quot Seq   6d  Sending mail to   s     quot   1  quot  2 quot        mail -s  quot This is not a spam    quot   quot  2 quot   lt  path to body     printf  quot  e 3D  done  n quot     mapfile  lt   lt  printf  quot  s 0 quot   quot  IN quot   -td    -c 1 -C myPubliMail   Note  the  0 at end of the format string is useless if you don t care about empty fields at end of the string or they re not present   mapfile  lt   lt  echo -n  quot  IN quot   -td    -c 1 -C myPubliMail    Seq       0  Sending mail to  bla some com   done    Seq       1  Sending mail to  john home com   done    Seq       2  Sending mail to  Full Name  lt fulnam other org gt    done   Or you could use  lt  lt  lt   and in the function body include some processing to drop the newline it adds  myPubliMail         local seq  1 dest  quot   2    n   quot      printf  quot Seq   6d  Sending mail to   s     quot   seq  quot  dest quot        mail -s  quot This is not a spam    quot   quot  dest quot   lt  path to body     printf  quot  e 3D  done  n quot     mapfile  lt  lt  lt  quot  IN quot  -td    -c 1 -C myPubliMail    Renders the same output    Seq       0  Sending mail to  bla some com   done    Seq       1  Sending mail to  john home com   done    Seq       2  Sending mail to  Full Name  lt fulnam other org gt    done    Split string based on delimiter in shell If you can t use bash  or if you want to write something that can be used in many different shells  you often can t use bashisms -- and this includes the arrays we ve been using in the solutions above  However  we don t need to use arrays to loop over  quot elements quot  of a string  There is a syntax used in many shells for deleting substrings of a string from the first or last occurrence of a pattern  Note that   is a wildcard that stands for zero or more characters   The lack of this approach in any solution posted so far is the main reason I m writing this answer      var  SubStr     drops substring from start of string up to first occurrence of  SubStr    var   SubStr    drops substring from start of string up to last occurrence of  SubStr    var SubStr      drops substring from last occurrence of  SubStr  to end of string   var  SubStr     drops substring from first occurrence of  SubStr  to end of string  As explained by Score Under     and   delete the shortest possible matching substring from the start and end of the string respectively  and    and    delete the longest possible matching substring   Using the above syntax  we can create an approach where we extract substring  quot elements quot  from the string by deleting the substrings up to or after the delimiter  The codeblock below works well in bash  including Mac OS s bash   dash  ksh  and busybox s ash  IN  quot bla some com john home com Full Name  lt fulnam other org gt  quot  while    quot  IN quot     do       extract the substring from start of string up to delimiter        this is the first  quot element quot  of the string      iter   IN          echo  quot  gt    iter  quot        if there s only one element left  set  IN  to an empty string        this causes us to exit this  while  loop        else  we delete the first  quot element quot  of the string from IN  and move onto the next         quot  IN quot     quot  iter quot     amp  amp            IN                 IN  quot   IN     quot    done    gt   bla some com     gt   john home com     gt   Full Name  lt fulnam other org gt    Have fun

User · Answer

In Bash  a bullet proof way  that will work even if your variable contains newlines  IFS     read -d    -ra array  lt   lt  printf   s  0   quot  in quot    Look    in   one two three   there is na newline nin this field    IFS     read -d    -ra array  lt   lt  printf   s  0   quot  in quot     declare -p array declare -a array    0   quot one quot   1   quot two three quot   2   quot   quot   3   quot there is a newline in this field quot     The trick for this to work is to use the -d option of read  delimiter  with an empty delimiter  so that read is forced to read everything it s fed  And we feed read with exactly the content of the variable in  with no trailing newline thanks to printf  Note that s we re also putting the delimiter in printf to ensure that the string passed to read has a trailing delimiter  Without it  read would trim potential trailing empty fields    in  one two three        there s an empty field   IFS     read -d    -ra array  lt   lt  printf   s  0   quot  in quot     declare -p array declare -a array    0   quot one quot   1   quot two quot   2   quot three quot   3   quot  quot     the trailing empty field is preserved   Update for Bash 4 4 Since Bash 4 4  the builtin mapfile  aka readarray  supports the -d option to specify a delimiter  Hence another canonical way is  mapfile -d     -t array  lt   lt  printf   s    quot  in quot

User · Answer

How about this one liner  if you re not using arrays   IFS     read ADDR1 ADDR2  lt  lt  lt  IN

User · Answer

Use the set built-in to load up the    array   IN  bla some com john home com  IFS      set  IN  IFS     t n    Then  let the party begin   echo    for a  do echo  a  done ADDR1  1 ADDR2  2

User · Answer

There are some cool answers here  errator esp    but for something analogous to split in other languages -- which is what I took the original question to mean -- I settled on this   IN  bla some com john home com  declare -a a     IN           Now   a 0      a 1    etc  are as you would expect  Use    a     for number of terms  Or to iterate  of course    for i in   a      do echo  i  done   IMPORTANT NOTE    This works in cases where there are no spaces to worry about  which solved my problem  but may not solve yours  Go with the  IFS solution s  in that case

User · Answer

I ve seen a couple of answers referencing the cut command  but they ve all been deleted   It s a little odd that nobody has elaborated on that  because I think it s one of the more useful commands for doing this type of thing  especially for parsing delimited log files   In the case of splitting this specific example into a bash script array  tr is probably more efficient  but cut can be used  and is more effective if you want to pull specific fields from the middle   Example     echo  bla some com john home com    cut -d     -f 1 bla some com   echo  bla some com john home com    cut -d     -f 2 john home com   You can obviously put that into a loop  and iterate the -f parameter to pull each field independently   This gets more useful when you have a delimited log file with rows like this   2015-04-27 12345 some action an attribute meta data   cut is very handy to be able to cat this file and select a particular field for further processing

User · Answer

Maybe not the most elegant solution  but works with   and spaces   IN  bla so me com   john home com  for i in  delims   IN         seq 1       delims    1    do    echo   gt    echo  IN   cut -d    -f i    done   Outputs   gt   bla so me com   gt       gt   john home com    Other example  delimiters at beginning and end    IN   bla so me com   john home com    gt      gt   bla so me com   gt       gt   john home com   gt       Basically it removes every character other than   making delims eg       Then it does for loop from 1 to number-of-delimiters as counted by    delims   The final step is to safely get the  ith part using cut

User · Answer

Taken from Bash shell script split array  IN  quot bla some com john home com quot  arrIN    IN        echo   arrIN 1                      Output  john home com  Explanation  This construction replaces all occurrences of      the initial    means global replace  in the string IN with      a single space   then interprets the space-delimited string as an array  that s what the surrounding parentheses do   The syntax used inside of the curly braces to replace each     character with a     character is called Parameter Expansion  There are some common gotchas   If the original string has spaces  you will need to use IFS    IFS      arrIN   IN   unset IFS    If the original string has spaces and the delimiter is a new line  you can set IFS with    IFS    n   arrIN   IN   unset IFS

User · Answer

Two bourne-ish alternatives where neither require bash arrays   Case 1  Keep it nice and simple  Use a NewLine as the Record-Separator    eg   IN  bla some com john home com   while read i  do     process   i      eg      echo   email  i   done  lt  lt  lt    IN    Note  in this first case no sub-process is forked to assist with list manipulation   Idea  Maybe it is worth using NL extensively internally  and only converting to a different RS when generating the final result externally   Case 2  Using a     as a record separator    eg   NL     IRS     ORS      conv IRS       exec tr   1    NL     conv ORS       exec tr   NL    1     IN  bla some com john home com  IN    conv IRS      lt  lt  lt    IN     while read i  do     process   i      eg      echo -n   email  i  ORS  done  lt  lt  lt    IN    In both cases a sub-list can be composed within the loop is persistent after the loop has completed   This is useful when manipulating lists in memory  instead storing lists in files   p s  keep calm and carry on B-

User · Answer

There are two simple methods   cat  text1 text2 text3    tr       n    and  cat  text1 text2 text3    sed -e  s    n g

User · Answer

echo  bla some com john home com    sed -e  s    n g  bla some com john home com

User · Answer

A one-liner to split a string separated by     into an array is   IN  bla some com john home com  ADDRS     IFS     echo   IN     echo   ADDRS 0   echo   ADDRS 1     This only sets IFS in a subshell  so you don t have to worry about saving and restoring its value

User · Answer

IN  bla some com john home com  IFS     read -a IN arr  lt  lt  lt     IN   for entry in    IN arr      do     echo  entry done   Output  bla some com john home com   System   Ubuntu 12 04 1

User · Answer

If no space  Why not this   IN  bla some com john home com  arr   echo  IN   tr            echo   arr 0   echo   arr 1

User · Answer

A different take on Darron s answer  this is how I do it   IN  bla some com john home com  read ADDR1 ADDR2  lt  lt  lt   IFS      echo  IN

User · Answer

Without setting the IFS  If you just have one colon you can do that   a  foo bar  b   a     c   a        you will get   b   foo c   bar

User · Answer

If you don t mind processing them immediately  I like to do this   for i in   echo  IN   tr       n   do     process done   You could use this kind of loop to initialize an array  but there s probably an easier way to do it  Hope this helps  though

User · Answer

Here is a clean 3-liner   in  foo bar bizz buzz fizz buzz buzz woof  IFS     list   in  for item in    list       do echo  item  done   where IFS delimit words based on the separator and    is used to create an array  Then     is used to return each item as a separate word   If you ve any code after that  you also need to restore  IFS  e g  unset IFS

User · Answer

This worked for me   string  1 2  echo  string   cut -d    -f1   output is 1 echo  string   cut -d    -f2   output is 2

User · Answer

There is a simple and smart way like this   echo  add sfff    xargs -d  -i  echo      But you must use gnu xargs  BSD xargs cant support -d delim   If you use apple mac like me   You can install gnu xargs    brew install findutils   then  echo  add sfff    gxargs -d  -i  echo

[bash] How do I split a string on a delimiter in Bash?

Examples related to bash

Examples related to shell

Examples related to split

Examples related to scripting